mongodrop slow on small db

I'm using a real Mongo instance for my integration tests. On every test, I call mongorestore my_db_state --drop because I need a clean db to start the next test.

On my tiny db (with only one test user account) it takes 180 ms to run mongorestore my_db_state (without --drop) and 455 ms with --drop.

I don't understand why it's taking so long to drop the db, but how can I speed this up?

I may have a bunch of different connections on the mongo server because I never close them on my Flask server, but they probably should be closed after the test is over...just not sure if this is an issue to care about.

Is there a faster way to restore a snapshot to its original state for testing purposes?