SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4703361c57bbc52fb206de49affaa189cb5ac6e328e76450b56f9ec93562b8ea' 
  AND token = '/BoBAQvEynIaKiPc2ikL8+/IsZXqFEFJFpxAhvm+qRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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