SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '125c4f8b8777e28cca4840ae819ace4bc893d53e7db8889f3f45574a132db196' 
  AND token = 'l6Mw9McRJXa2lEsMb4haWg3ab+66ydkxEjjtXqKfH9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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