SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fe38cfd385b5c7650327b312f33352db9d4b61cd50bd2d2a09c981afad708404' 
  AND token = 'XnYtsSTaB3rmWUdR4ugVZX4S4IdAToVfvjqKqQT1Tcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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