SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49a689aadd4cb68f235e05ba445fa56626f44eb076f452fa74da6ed27d648caa' 
  AND token = 'i39edvzD/fvRwOqKCc5RsiTWUiTqS2Ao5Yvn7wNUf3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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