I am hosting a WP website on a VPS (Debian) and I noticed that my MySQL service is constantly being processed, even without any active live visitors that I can see on Google Analytics.

I am aware that there are crawlers from search engines that try to get the content.

Is there a valid way to prevent overloading my MySQL service by ghost visitors (force visitors to be processed via the Google Analytics? Enable Java?)? Or prevent unwanted bots and crawlers?