SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5462ac0807e705ed0eb5212ee018893666b53008a573c5980826779fefc6bd9f' 
  AND token = 'XkeDG3RRZOY5/whRmONyUWzKhGg3tG5hJasl4eLca+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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