I have no idea what these are but they came on a MB I bought S-Hand 12 years ago or more. The little ridge at the back is the only thing that ever trapped my foot in the cage as I kept the straps a bit loose. I had lotto runners with a groove in just the right place to catch the ridge, that's what probably made them work. Later I tried a set with serrated teeth and found them too tricky to get out of.

This is the closest thing I could find online.
Buy Wellgo Track Fixie Bike Pedals Toe Clips and Leather Straps | CD

Take care of that little toddler