Having both free and paid API keys on the same account

Hi, if I upgrade to paid plan can I still keep my old free plan API key on the same account
OR
Does switching to paid plan automatically removes the free plan from the account?

Learning from suggested topics - I’ve figured I need to create separate project to separate the api keys where I could potentially set up billing for one of the projects

Please do keep in mind when using free , everything you do or alter or change or train in terms of the model the company is allowed to use and or integrate with their services or products the paid services gives you a little bit more of an exclusion right over the knowledge or data so paying for the service and still using a free key is contradictory in terms of your goal