If your Credit Karma account is expired, the bank will probably bounce the refund. But, don't worry. The money won't disappear. The bank will send it back to the IRS and your full refund will be mailed as a check to the address you have on your return.
Reach out to Credit Karma as soon as possible, to see how your account is doing: CreditKarma contact.
If the return has already been filed and accepted, you won't be able to make any changes. On the other hand, if your return hasn't been filed yet, you can open another account.