Lots of convenience stores sell fresh doughnuts every day. Usually these are delivered in the middle of the night to stores so that they can have fresh ones for the morning customers.
This is great, if you like doughnuts. However, there is only one good time to get those doughnuts. After that, you don't want to have anything to do with them.
My advice? Only buy those fresh doughnuts if you work early in the morning. I get to work at 6am. The doughnuts are usually delivered sometime around 4am. So I can't vouch what has happened to them by the time I get there 2 hours later, but I can tell you what I observe.
Usually around 6:30am we get our first morning rush. These people are usually okay, because they are often too tired to eat and just want their coffee. The doughnuts are not usually touched at this time.
Our 7am customers are a little more awake and are looking for some food before getting to the office.
They will then spot the doughnut case.
It is then that I see, during this morning rush, doughnuts picked up, inspected, then put back down.
I will see people pick up a doughnut, decide they don't want it and put it back down, then lick the frosting or glaze off their fingers and then go pick up another one. Usually they take that one, but I've seen people put that one back too and continue to pick up various doughnuts with their recently licked fingers.
I've seen people poke doughnuts to see how soft they are and then grab another one that they didn't just touch.
I've seen people cough and sneeze all over the doughnuts in the case.
I've even seen people drop a doughnut on the floor, pick it up and then put it back in the case. (That is when I step in, pull it out of the doughnut case and make them pay for it).
I am very observant. And 99% of the time I will never buy a fresh doughnut past 7am.
Conclusion: You only have a half hour window in which to get fresh, untouched, unsneezed, unlicked and undropped doughnuts: 6:30am - 7am. If it's after that time, you'd be better off eating from a garbage can.