How to change the order in which Views SQL joins are executed?
You are looking for the following:
https://api.drupal.org/api/views/views.api.php/function/hook_views_query_alter/7
It will work roughly as follows:
You will find that there is a clauses array in your query object among others that will contains your restraints. Remove the particular element, and insert it into the correct order in the array. They will be executed 0 through N