what is the fast way to prepare test db? slimming mysql db
MySQL doesn't contain any built-in way of marking rows when they're accessed. You could conceivably use triggers to record updates, inserts, and deletes, but not selects.

It's conceivable that somebody could adapt the alpha-quality MySQL proxy server, or the MySQL relay, to build a recording proxy. But that would be a lot of work, and it would yield the queries.