Killed Query in error log caused by wp-smush

Hi there,

Since I've activated wp-smush-pro in my projects I've watched in error logs as you can see in attachment that the plugin is making too long queries that it cause error as you can see as "Killed Query" in log.

I'd like to know why it happens and what could be done to fix it because according to WP Engine, our Wordpress hosting it's impacting the project.