When you get a traffic citation of any kind, it becomes listed as "Open" in the traffic citation database of the city, county or state (depending on who exactly gave you the citation). When you pay that citation, once the payment gets processed the citation is cleared from the database and marked closed. If you want to make sure that your payment has gone through successfully, you can check in a few different ways.
Find the original traffic citation that you were given at the time you violated local area traffic laws. This citation will have all the information needed to see whether or not your citation has been cleared in the local database.
Call the telephone number listed on your citation. Provide the person you speak with the case number (also listed on the citation), and they will be able to check the updated database and see whether or not your payment has been accepted and whether the citation has been marked as "closed" on their end of the transaction. If it hasn't, they will also be able to tell you what you should do.
Go to the website address listed on the bottom of the traffic citation. Many jurisdictions allow you to check the status of traffic citations on the Internet (though not all will have this option, depending on the area of the country you got the citation in). Go to the website, type in the original case number that is listed on the citation to view the record. If your payment has cleared, the status of the citation will be listed as "Closed" as opposed to "Open."