SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6589ffccb5c3b6198bc3959f16a5bbdd124c7888be82fb06de0eb0f68a15fd5e' 
  AND token = 'uysGqv9NDWcancIblYnMU8dK0TcmROAKD3w1xFrxk1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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