MDF finish question

Greetings all. I made a table/cabinet for some printers in my home office. I used MDF, and it was the first time. It came out great, I've been using it since January. I don't have a lot of space in my house to work, so I waiting until summer to finish it.

I figured I could paint it. I primed first, then painted with cabinet paint. It came out decent enough, but I'm worry the paint will just chip and scratch off too easily.

What can/should I use as a top coat? I've never worked on MDF before this, and all my other projects were wood and had a natural finish. I have no idea what to put over paint.

Thanks in advance.