Not to my knowledge. It's not an idle question, though -- the suggestion that physical constants might have changed over time arose not arbitrarily, but as a result of work in theoretical physics (Dirac's large number hypothesis, as well as a number of models that predict non-constant constants).

Remember that just over a hundred years ago one might equally well have asked "in the history of science, how many things have been shown to have constant velocity in all reference frames?"