MySQL query increase kill time in which file?

[Designinfo]

How to increase the time for query killing so as to prevent crowding in increase page load time.

 I have been facing these queries which are crowding my server as reported by my server assistant. 

 

Thu Jun 18 09:56:15 +0000 2015 [info] killed_thread_id:11508142 user:pres102 host:localhost db:pres102 command:Sleep time:21 query:

 

these are repeatedly being displayed in the list of killed queries. In which file do I make the changes for these queries to be resolved correctly? Also what other changes in which file I should make to kill other queries. I do not know the file name in PrestaShop where such queries and their changes should be made. Please help.