SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35a43e7257f76baa4371572e97669fb0e6df913e48a13654d31da71b41150c2e' 
  AND token = 'EbTTN9g0ZCDCY2YgWmrT7ONof6kee1IE+vPNhqrduk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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