Hi Russell
So through either the slow query log, or catching it via SHOW FULL PROCESSLIST, or for a
more extreme solution enabling the general query log (you can set it up with the path, but
only enable it for a bit and then turn it off again - it would create a lot of stuffs),
catch the actual query.
Then run it with EXPLAIN <query>
Post that the output from that here.
Also it might be good to paste your SHOW TABLE STATUS for those tables here, I might be
able to see more from that.
And perhaps
SHOW CREATE TABLE <tblname> \G
from the mysql cmdline client for the table structure of each of these tables.
At this point I wouldn't fuss with switching from MySQL to MariaDB, MySQL does a fine
job generally.
MySQL 5.6 is EOL now though, so something a bit newer might be good.
Regards,
Arjen.