So I had to take matters into my own hands and make one myself.
I used some boxes I had on hand and taped them together so they'd be as big as I needed. I used one set of boxes for our wooden trains and track, and another set of boxes for our duplo blocks. These boxes are about 3.5 inches tall, 13 inches wide and 36 inches deep. They fit perfectly under the love seat....
... and are completely hidden out of sight when not in use.
Clean up is a breeze, just throw the toys into the box and slide it under the sofa.
What clever ways have you used to store toys?