Pymongo cursor taking ~ 2 seconds, please suggest ways to optimize below query.

*Facts of query*

Records in MongoDB : 120,000
Indexed Key: emp_id
MongoDB Server: 3.2.11
PyMongo : 3.5
Python : 2.7

*Cursor*

To find a document from db, by using indexed field as filter and projecting only required fields, its consuming ~2 Seconds.

I am looking for ways to optimize this query so that it can be faster.

    user_data = MongoldbAdaptor(**APP_CONFIG).db().collection_name.find_one(
        {"emp_id": 1234}, {'nameFirst': 1, 'nameLast': 1, 'emp_id': 1, }
    )

Elapsed Time: 1.829226017
_____________________________________________________________________________________
For Informational purpose, please refer same query using find()

    def query_cursor():
        cursor = MongoldbAdaptor(**APP_CONFIG).db().collection_name.find(
            {"emp_id": 1234}, {'nameFirst': 1, 'nameLast': 1, 'emp_id': 1, }
        ).limit(1)
        
        return cursor
    
    def get_user_data():
        cursor = query_user_data()
        user_data = None
        for document in cursor:
            user_data = document
        return user_data
    
    print(get_user_data())

Elapsed Time for query_cursor: 0.00215888023376

Elapsed Time for get_user_data: 1.79128599167