Keep in mind that if the ‘donut’ spare is on the driven wheels, that the “50 mile” rating and the low speed is to keep the axle’s gearset from excessive wear and overheating due to the mismatched tire sizes, and not because the tire is going to wear out.
The spare is probably far better than the tire you show in the picture… I hope the rest of them aren’t that bad. I haven’t been dumb enough to drive on tires like that since I was a 17 year-old @#$! head though… Scrape up and get a decent cheap set of tires all-round and your driving will be much more enjoyable. (I’d avoid General tires)