Do yellow lentils sprout after submersion for a few hours?
First off, no they are almost certainly not dead worms. 

What you are looking at inside the lentil seed is the embryo of the future lentil plant. Soaking makes the whole seed expand as it takes up the water, and sometimes the two halves of the seed come apart so you can see these little plant embryos better. But they are contained in the seeds all the time, even before you start soaking them. When you eat peanuts (also legume seeds, just like lentils are), if you look at the inside of a split open one, you can see the embryonic plant really well because they are so big. 

Maybe technically speaking, your lentils are sprouting in some microscopic way from the moment they hit the soaking water, but usually when people say "sprouting", they are talking about when the little root of the plant has started to develop and starts poking out of the seed in a visible way. This wouldn't happen in just 3-4 hours. Maybe at the very least a couple days. 

As far as the age of your lentils, 30 months isn't too long at all as far as edibility goes (as long as you kept them dry and in decent conditions), so don't throw them out. If you bought them intending them exclusively for sprouts, sorry, I don't know whether 30 months is long enough to diminish their "sproutability" significantly. But I'd be surprised if at least some of them wouldn't start to sprout after a few days.

Also, sorry I can't answer about sprouting more readily depending on the season. Certainly beans will sprout all times of the year, but maybe someone with more experience can say if they do it quicker in the spring or not.