User listing in wp-admin user.php / user list page

Question

I need to display some custom order in user list page, but I need to use two type of meta_keys, one is working how can I add another one?

This is I tried with one with meta_key, I need another one (meta_key) to use

$query->set('meta_key', 'my_user_dob');
$query->set('meta_compare', '<');
$query->set('meta_value', 'Value');      

No errors found in this code, but I need to insert another meta_key

$query->set('meta_key', 'my_user_dob');
$query->set('meta_compare', '<');
$query->set('meta_value', 'Value');