SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee2b7a80de8cf6a507c4f45e648f9115377b1c1f2bb89a61c3993a8b15ef6cd3' 
  AND token = 'AZCvobMudt2HyjBnil9dQpBtBtGpGZZ+jqvhrKmPVsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}