I have the best luck with lettuce indoors at around 75 degrees and generally speaking it sprouts for me in about 2 or 3 days. After that though, it does like it cool or at least shaded. I should also mention, this is for Black Seeded Simpson lettuce. Different varieties have different requirements.
The chard and kale are different beasts. Kale usually takes close to 2 weeks for me, and chard, well, I've not had much luck with. But Alex left a helpful note so I may be able to use that to my advantage next time. I'm betting I didn't keep the "seeds" moist for long enough to get through that tough pod. Maybe I'll try breaking it open next time!