At 60,000 editors will raise an eyebrow, but not necessarily reject out of hand. Some editors never look at the word count on a novel manuscript. Instead, they heft it, look at the typeface. If it seems really long they will be skeptical and waiting to be convinced. If it seems really short, the editor had better be grabbed strongly in the first few sentences.
Market forces make a very short book difficult.
They'll feel ripped off. In fact, a lot of places won't stock low price-point titles at all. So you're better off writing a novel between 60,000 and 90,000 words. Only if the editor thinks the work is otherwise exciting, and can be improved by the cutting or additions. Please don't think that this length business is some kind of formula for making a sale.