Hot MOSFET DC-DC Boost Converter
You appear to be driving the MOSFET with a 5V p-p signal - this is usually nowhere near enough to adequately turn these devices on - that is why it gets so warm. I'll also add that you haven't chosen a great FET for this application - it's a 250 volt rated FET with an on-resistance of typically 0.22 ohms. Clearly, the maximum voltage you are generating is going to be about 50V (due to the 63V rated cap on the output) - you should be looking for a MOSFET with about one-tenth the on-resistance and driving it at least 10V p-p.

In short, I'd say this is a bad choice of MOSFET.