What is it?
EXPLAIN ANALYZE is a profiling tool for your queries that will show you where MySQL spends time on your query and why. It will plan the query, instrument it and execute it while counting rows and measuring time spent at various points in the execution plan. When execution finishes, EXPLAIN ANALYZE will print the plan and the measurements instead of the query result.
This new feature is built on top of the regular EXPLAIN query plan inspection tool, and can be seen as an extension of the EXPLAIN FORMAT=TREE that was added earlier in MySQL 8.0. In addition to the query plan and estimated costs, which a normal EXPLAIN will print, EXPLAIN ANALYZE also prints the actual costs of individual iterators in the execution plan.