Disable transient query

Transients are used as a way of caching the results of some particular operation or query. Removing the transient could result in more and more complex DB queries. https://developer.www.ads-software.com/apis/handbook/transients/

You can “move” transients outside of mysql, in case you use redis or memcached
You will need your host to support it,
and a plugin helper like https://www.ads-software.com/plugins/redis-cache/ (for redis)
It will work much faster than with mysql, but even if transients are stored in wp_options table its still better than live without them (no, you cannot disable transients, WordPress needs them)

Old stale transients can be cleaned by many optimizing plugin, or this one (doing just this): https://www.ads-software.com/plugins/delete-expired-transients/

I managed to solve the loading problem by adding memcached on database.
Now, may i ask, offtopic, if i add cache on page also, using memcache, is a good ideea? Now i’m using disk cache for pages and memcache for db.