You need to ask your bank if a locked card will stop a subscription from being charged to the your account. Different banks do it differently.
However, a subscription is a contract and not paying a subscription does not remove the obligation to pay. For example, if you have a subscription for an app/game on Apple App Store, not paying the subscription does not stop the charges accumulating on your account and Apple locking your accounts and Apple ID until payment is made in full.
Subscriptions must be canceled to stop the charges.