Yes, in order to sort y a meta cay you need to use that field for meta_key. Should have seen this but I missed it. In order to sort by your time field but select posts based on
'meta_key' => 'contest_route',
'meta_value' => 'route_small',
you’re going to need to use a meta_query rather than the above for contest_route. meta_query is an array. Look at the meta_query section of https://codex.wordpress.org/Class_Reference/WP_Query
