SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12128b84de49862c72b848e2343670afed57b289c7c8d1427af1d38a610250df' 
  AND token = '77VjTADGjA3H6qjQPpXF8TcBssXn7Bd0L9p/RTyDtEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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