SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3aca4744b259eaa675bd964a39b3290b464d44781190ce1cc3acab6675b1779' 
  AND token = 'YeFcjxvr2bGPheZ4cmPbOkYCIoUSe9iKit+5RxtdhnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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