I learned as a kid when I kept snakes that I'm too absent minded to be able to safely trust myself to always remember to latch a lid after I close it, so hasps like those, that need to be flipped down and maybe also have a stick put through the hole, aren't safe for me. I wanted a top that would latch itself just by being closed, so came up with a design that works great, and is easy to put together, but a little hard to explain, so I hope this picture helps:
The important thing to realize, which isn't obvious in the picture, is that the round rod is only attached at the far end, where it is inserted into a 1" long piece of hollow square tubing. The square tube piece is glued down to the top/door/lid, leaving the rest of the length of round rod floating 1/16" above the surface of the top/door, and able to easily flex an inch or two left, right, or up when I grab the free end of the rod. To open the top, I grab the free end of the round rod, flex it a little to the left so that it clears the hook, and then lift it up, opening the hinged top. When I close the top, or as it falls closed by gravity when I simply let go of it, the rod hits the angled part of the hook, which flexes the rod to the left as it moves down until the lid closes far enough that the rod springs back to the right into that notch in the hook. The little rectangular thing that encloses the near end of the round rod is glued down to the top, not the rod, and acts as a guard rail to limit how far left, or up, the rod can be flexed, making it hard for me to accidentally over flex the rod and break it. When I lift up on the near end of the rod to open the lid, the near end of the rod pushes up on the underside of that little rectangular rail, and so lifts the lid from its front edge, rather than putting too much torque on the far end of the rod where it's glued to the lid near the hinged side. I made the "rail" by cutting a 1/4" length off the end of some 3/4" square acrylic tubing, and then cutting that in half to get two of those little three sided rails. The I just glued it down to the acrylic top, straddling the round rod.
Anyway, this latch setup works perfectly, and is foolproof - just close the lid. My bimac (crazy strong) can push as hard as he wants, and will never be able to lift the lid, and I'll never forget to latch the lid. The 1/4" round acrylic rod, square acrylic tubing, and 1/4"x 3/4" rectangular rod (to make the "hook") can all be ordered fairly cheaply from eplastics.com, as well as the acrylic hinges, Weld-on, etc.