How in Mongoose to track the uniqueness of the field when adding (I have two options)?

Question

Node.js

The document has two unique fields.
You can catch this moment using autoIndex: true.
But in production it is recommended to turn it off.
I have two options:
1) Leave.
2) Do find, if there is a match - do not save. Cons - two extra calls to the database (two finds for two fields).