There are two species of locust (at least, that I know of anyway.) Black locust with the deeply ridged bark and honey locust typically with the near-lethal thorns. Hopefully for you, you have BL.
I've seen some BL trees around here that were felled or blown down many years back. The heartwood was just fine, and difficult to cut as usual. Only rot visible was in small limb cavities, and very little of that.
Once cut and split, it still took a while to dry to equilibrium moisture content. Once it dried like that, it was really fine stuff. Like any wood, how and where you stack it will affect the finished product.
Even air-dried as much as possible here, it just doesn't work for me to load the stove with only BL. Adding in a stick or two of more volatile wood helps a lot. Ash, maple, birch are good.