SERVER-82549 - Here is explain() for the slow query WHEN HINTED:

{
  "explainVersion": "2",
  "queryPlanner": {
    "namespace": "XXX_production.customers",
    "indexFilterSet": false,
    "parsedQuery": {
      "$and": [
        {
          "customer_user_id": {
            "$eq": "6267a29a50102f009b84e9d1"
          }
        },
        {
          "franchise_id": {
            "$eq": "5b3069a900869bb32e00143f"
          }
        }
      ]
    },
    "queryHash": "91BCEF24",
    "planCacheKey": "65161574",
    "maxIndexedOrSolutionsReached": false,
    "maxIndexedAndSolutionsReached": false,
    "maxScansToExplodeReached": false,
    "winningPlan": {
      "queryPlan": {
        "stage": "FETCH",
        "planNodeId": 2,
        "filter": {
          "franchise_id": {
            "$eq": "5b3069a900869bb32e00143f"
          }
        },
        "inputStage": {
          "stage": "IXSCAN",
          "planNodeId": 1,
          "keyPattern": {
            "customer_user_id": 1
          },
          "indexName": "customer_user_id_1",
          "isMultiKey": false,
          "multiKeyPaths": {
            "customer_user_id": [            ]
          },
          "isUnique": false,
          "isSparse": false,
          "isPartial": false,
          "indexVersion": 1,
          "direction": "forward",
          "indexBounds": {
            "customer_user_id": [
              "[ObjectId('6267a29a50102f009b84e9d1'), ObjectId('6267a29a50102f009b84e9d1')]"
            ]
          }
        }
      },
      "slotBasedPlan": {
        "slots": "$$RESULT=s12 env: { s3 = Timestamp(1698578575, 1859) (CLUSTER_TIME), s15 = bsonObjectId(\"5b3069a900869bb32e00143f\"), s11 = {\"customer_user_id\" : 1}, s2 = Nothing (SEARCH_META), s1 = TimeZoneDatabase(US/Arizona...Asia/Ujung_Pandang) (timeZoneDB), s4 = 1698578575716 (NOW), s7 = KS(646267A29A50102F009B84E9D1FE04), s6 = KS(646267A29A50102F009B84E9D10104) }",
        "stages": "[2] filter {traverseF(s14, lambda(l1.0) { ((l1.0 == s15) ?: false) }, false)} \n[2] nlj inner [] [s5, s8, s9, s10, s11] \n    left \n        [1] cfilter {(exists(s6) && exists(s7))} \n        [1] ixseek s6 s7 s10 s5 s8 s9 [] @\"88869198-6429-48f7-9219-c970de48931f\" @\"customer_user_id_1\" true \n    right \n        [2] limit 1 \n        [2] seek s5 s12 s13 s8 s9 s10 s11 [s14 = franchise_id] @\"88869198-6429-48f7-9219-c970de48931f\" true false \n"
      }
    },
    "rejectedPlans": [    ]
  },
  "executionStats": {
    "executionSuccess": true,
    "nReturned": 1,
    "executionTimeMillis": 1,
    "totalKeysExamined": 2,
    "totalDocsExamined": 2,
    "executionStages": {
      "stage": "filter",
      "planNodeId": 2,
      "nReturned": 1,
      "executionTimeMillisEstimate": 0,
      "opens": 1,
      "closes": 1,
      "saveState": 0,
      "restoreState": 0,
      "isEOF": 1,
      "numTested": 2,
      "filter": "traverseF(s14, lambda(l1.0) { ((l1.0 == s15) ?: false) }, false) ",
      "inputStage": {
        "stage": "nlj",
        "planNodeId": 2,
        "nReturned": 2,
        "executionTimeMillisEstimate": 0,
        "opens": 1,
        "closes": 1,
        "saveState": 0,
        "restoreState": 0,
        "isEOF": 1,
        "totalDocsExamined": 2,
        "totalKeysExamined": 2,
        "collectionScans": 0,
        "collectionSeeks": 2,
        "indexScans": 0,
        "indexSeeks": 1,
        "indexesUsed": [
          "customer_user_id_1"
        ],
        "innerOpens": 2,
        "innerCloses": 1,
        "outerProjects": [        ],
        "outerCorrelated": [
          5,
          8,
          9,
          10,
          11
        ],
        "outerStage": {
          "stage": "cfilter",
          "planNodeId": 1,
          "nReturned": 2,
          "executionTimeMillisEstimate": 0,
          "opens": 1,
          "closes": 1,
          "saveState": 0,
          "restoreState": 0,
          "isEOF": 1,
          "numTested": 1,
          "filter": "(exists(s6) && exists(s7)) ",
          "inputStage": {
            "stage": "ixseek",
            "planNodeId": 1,
            "nReturned": 2,
            "executionTimeMillisEstimate": 0,
            "opens": 1,
            "closes": 1,
            "saveState": 0,
            "restoreState": 0,
            "isEOF": 1,
            "indexName": "customer_user_id_1",
            "keysExamined": 2,
            "seeks": 1,
            "numReads": 3,
            "indexKeySlot": 10,
            "recordIdSlot": 5,
            "snapshotIdSlot": 8,
            "indexIdentSlot": 9,
            "outputSlots": [            ],
            "indexKeysToInclude": "00000000000000000000000000000000",
            "seekKeyLow": "s6 ",
            "seekKeyHigh": "s7 "
          }
        },
        "innerStage": {
          "stage": "limit",
          "planNodeId": 2,
          "nReturned": 2,
          "executionTimeMillisEstimate": 0,
          "opens": 2,
          "closes": 1,
          "saveState": 0,
          "restoreState": 0,
          "isEOF": 1,
          "limit": 1,
          "inputStage": {
            "stage": "seek",
            "planNodeId": 2,
            "nReturned": 2,
            "executionTimeMillisEstimate": 0,
            "opens": 2,
            "closes": 1,
            "saveState": 0,
            "restoreState": 0,
            "isEOF": 0,
            "numReads": 2,
            "recordSlot": 12,
            "recordIdSlot": 13,
            "seekKeySlot": 5,
            "snapshotIdSlot": 8,
            "indexIdentSlot": 9,
            "indexKeySlot": 10,
            "indexKeyPatternSlot": 11,
            "fields": [
              "franchise_id"
            ],
            "outputSlots": [
              14
            ]
          }
        }
      }
    },
    "allPlansExecution": [    ]
  },
  "command": {
    "find": "customers",
    "filter": {
      "franchise_id": "5b3069a900869bb32e00143f",
      "customer_user_id": "6267a29a50102f009b84e9d1"
    },
    "hint": {
      "customer_user_id": 1
    },
    "$db": "tablesolution_production"
  },
  "serverInfo": {
    "host": "atlas-tzcwdx-shard-00-00.uhz3j.mongodb.net",
    "port": 27017,
    "version": "7.0.2",
    "gitVersion": "02b3c655e1302209ef046da6ba3ef6749dd0b62a"
  },
  "serverParameters": {
    "internalQueryFacetBufferSizeBytes": 104857600,
    "internalQueryFacetMaxOutputDocSizeBytes": 104857600,
    "internalLookupStageIntermediateDocumentMaxSizeBytes": 104857600,
    "internalDocumentSourceGroupMaxMemoryBytes": 104857600,
    "internalQueryMaxBlockingSortMemoryUsageBytes": 104857600,
    "internalQueryProhibitBlockingMergeOnMongoS": 0,
    "internalQueryMaxAddToSetBytes": 104857600,
    "internalDocumentSourceSetWindowFieldsMaxMemoryBytes": 104857600,
    "internalQueryFrameworkControl": "trySbeEngine"
  },
  "ok": 1.0,
  "$clusterTime": {
    "clusterTime": {
      "$timestamp": {
        "t": 1698578575,
        "i": 1865
      }
    },
    "signature": {
      "hash": {
        "$binary": {
          "base64": "OUxh3FNf9Bqk3yz0sOQz5OtU/cg=",
          "subType": "00"
        }
      },
      "keyId": 7250897925230821726
    }
  },
  "operationTime": {
    "$timestamp": {
      "t": 1698578575,
      "i": 1855
    }
  }
}