You can optimize MySQL queries by first checking where problems are coming from. When you see an unexpectedly large number of queries, check your String Translation Tracking and Auto ID Adjust as potential sources.
To learn more about identifying performance issues using the Debug Objects plugin, visit our FAQ on debugging performance problems.
How to optimize String Translation Tracking?
String Translation Tracking triggers SQL queries when you’re logged in as Admin. To enhance performance, navigate to WPML → String Translation and make sure that Track where strings appear on the site is not checked.
How to optimize Auto ID Adjust?
If Adjust IDs for multilingual functionality is selected, WPML will perform SQL queries whenever the theme tries to load items with specific IDs.
You can disable this option in in WPML → Languages → Make themes work multilingual and use icl_object_id and other functions from WPML’s API instead, to turn your theme multilingual.