The key is typically part of the blade adapter, but since it is a Honda, they can't make things easy. The bolt is not sacrificial; there was sufficient energy to overtighten and break the bolt after the key was sheared. Given that those have a weak 5/8 crankshaft and the weight of two blades, I can assure you that the crank is bent. I have junked more Honda lawn mowers with bent cranks or other problems, like cracked blocks, than I can remember. More than any other brand, by far. The remainder of the bolt is still inside the crankshaft in the photo. It is almost impossible to remove it. Not a good day for you or Honda.