Seems like a reasonable idea. Two things to consider:
Can you get a crank shorter enough to make a difference? Common crank lengths are 170, 172.5 and 175mm. (measured from crank axle center to pedal axle center). Shorter lengths are also available for some cranks, in 2.5mm increments.
I think you would have to do some experiments and measurements. Say you went from a 172.5mm crank (the most common length) to a 168.5mm one. That would allow you to drop the seat 5mm and keep the same amount of knee flexion. Is that enough to enable you to touch the ground safely?
Crank availability. I looked at a few pictures of the Claud Butler Explorer. Models at least a few years old seemed to have a 3-piece crank with a square taper axle-crank interface. That's good as the square taper is an old standard, so used but perfectly serviceable cranks are available, new ones are inexpensive also. The left are right cranks do not have to match, so you can use any that you can find in the right length.
Square taper cranks need a special tool to get off, but a good local bike shop can do it for you.