Having never done a Mr. Beer, I don't know how you carbonate your beer, I would assume sugar of some sort. Temperature will not affect how your beer carbonates.
How your beer tastes is a very different story. S23 is most comfortable around 45 degrees. Having it 30 degrees higher than that won't kill the yeast or make it not work, but your beer has a very high chance of gathering some weird tasting stuff.
Perhaps someone with some more Mr. Beer experience can help you with why it didn't carbonate, but all I can tell you is the reason is probably not temperature.