After you pay off your credit card debt the credit card company should report the paid off balance on the credit card to the credit bureau's within 30 days but it can take up to 45 days to show up on your credit report as being paid.
It can take up to 90 days for your credit score to improve after the credit card balance has been reported as paid though.
So you'll need to be patient. It can take awhile for your credit score to improve after paying off a credit card or other debt.