How do I disable update checks for locked projects?
drush cron will trigger the default update manager search, whereas locked project are only locked during drush pm-updatestatus. If you want to prevent Update Manager from checking for particular modules, you'll need a custom module that implements hook_update_projects_alter. All you have to do then is unset($projects['context_mobile_detect']);.

E.g.

/**
 * Implements hook_update_projects_alter().
 */
function MYMODULE_update_projects_alter(&amp;$projects) {
  unset($projects['context_mobile_detect']);
}


I do this quite a lot for Features modules, or custom code.