Query Cache in mariaex/myxql

How do I cache single queries with MySQL drivers?

Mariaex has a LRU cache for all queries.

MyXQL has an opt-in cache using an :cache_statement option (put a unique value per query there) to MyXQL.query. If you are using it with Ecto, it already sets the cache option for most queries.

How do I know it works? Can I see it on the db?