I'm sure the title, if it ever existed, would be extinct by now.
But the thing is, I'm not sure there ever was a title. Sir Nicholas Byron-579 was a knight,his knighting was a matter of record, he styled himself as a knight, not a baronet. So if his descendants would have a baronetcy, it would have to have come from him, and I don't see that he had one.
But then how did the descendants get away with using it?