Faster way to retrieve account balances on Fortnox

I am using the following view to retrieve the account balances:

create or replace view AccountActiveBalances
as
select act.Number AccountNumber
,      act.Description AccountDescription
,      act.Active AccountActive
,      act.Year AccountYear
,      anr.Account_BalanceBroughtForward BalanceBroughtForward
,      anr.Account_balanceCarriedForward BalanceCarriedForward
from   Accounts@fnx act
join   Fortnox.Accounts.AccountByNumber@fnx(act.number) anr
where  act.Active = true

But it is very slow, like 10+ minutes, for 558 active accounts.

Is there any way to retrieve the balances in a more quick way, say within 30 seconds?