SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03c28399469381d8ea39ac2c4ef1d43eab16a39c4813a23d28a6512c62c5d24f' 
  AND token = 'Hgq+iNvJtPm/+u7jHhlXmYxVN/yd2P5Y07zXX2U6nNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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