MongoDB - Slow aggregate query

It takes around **6min** to get the result from MongoDB, when I use the following aggregate query. db.barcodes.aggregate([ { $lookup: { from: 'company', localField: 'company', foreignField: '_id', as: 'company' } }, { $match: { 'company.name': 'ABCd' } } ]); I have two collections in my DB, company and barcode. If I search with text **'ABC'** *(instead of **'ABCd'**, company name 'ABC' already exists in the DB)* it takes only **0.05Sec** to complete the result. Total **42,14,301** documents in barcode collection and 2 documents in company collection. **Sample documents** Company { "_id" : ObjectId("615dd7873c4f710b71438772"), "name" : "ABC", "isActive" : true } Barcode { "_id" : ObjectId("615dd8ff3c4f710b71438773"), "barcode" : "1", "company" : ObjectId("615dd7873c4f710b71438772"), "comment" : "text 1" } **Indexed fields** - company._id - company.name - company.isActive - barcode.company - barcode._id Mongo clients used: Studio 3t and MongoDB CLI **Output of explain** { "stages" : [ { "$cursor" : { "query" : { }, "queryPlanner" : { "plannerVersion" : 1.0, "namespace" : "diet.barcodes", "indexFilterSet" : false, "parsedQuery" : { }, "winningPlan" : { "stage" : "COLLSCAN", "direction" : "forward" }, "rejectedPlans" : [ ] } } }, { "$lookup" : { "from" : "company", "as" : "company", "localField" : "company", "foreignField" : "_id" } }, { "$match" : { "company.name" : { "$eq" : "ABCd" } } } ], "ok" : 1.0 }