A:AnswerAll online games require subscription to PS Plus. You do not have to use credit card to do this when you have prepaid card. In the account settings be sure to UNCHECK AUTO AUTO RENEWAL to prevent further charges in the case that you DO HAVE credit card stored. Hope this helped.
A:AnswerFrom store.playstation.com
Log into your PSN account
From the dropdown menu that is your PSN name, click on Subscriptions Management and your PS Plus expiration date will appear.