Malaysian credit cards cannot be used to directly purchase games from US PSN store.
It will give an error during the verification $1 charge by Sony.

This might have changed now, but you can try it first and see if it works for your credit cards.
Refer :
https://forum.lowyat.net/index.php?showtopic=1049055


What I did instead, is to purchase top up PlayStation Store Gift Card [Digital Code] from USA Amazon.com account using Malaysian credit card, but set the Amazon account default billing to USA address.

Depending on the billing address, most US states are charging taxes on the Gift Card/PSN membership but some states are tax free, so just set your Amazon billing account to an address in these tax-free states.

This post has been edited by Hattori: Mar 25 2019, 01:51 PM

This is because the US PSN cards are not meant for sale outside US.
They will always show "Currently unavailable" because auto detect the delivery location is Malaysia.

If you login with your Amazon account and your saved address is US, then it is available.

Clear your browser's cache/cookies and relogin ?