There was a related thread a few months back, here:
Touring Shoe Recommendations?

Before you give up on your existing shoes, try moving the cleats as far back on the shoe as allowed. My feet are happier with the cleats further back.

If your existing shoe has removeable insoles, pull the insoles out and see if there is a smooth firm foot bed under the insole. Some shoes have the cleat hardware exposed there and if the insole is not firm enough, you could have problems from that. On several of my shoes, I cut a piece of steel sheet metal to fit between that foot bed and the removable insole, taped into place. That provides the firm smooth flat footbed that I need under the removable insole.

For example, I had a pair of Pearl Izumi shoes a couple decades ago that felt very good, until I had gone about 15 or 20 miles, then they were pure agony. There was a very soft piece of foam covering the cleat hardware under the removable insole. And my foot would press into that soft foam, essentially I was trying to press the ball of my foot into a tiny little square hole as I rode. The sheet steel provided a flat firm foot bed for support. I have done that on several pairs of shoes that did not have a smooth firm foot bed under the ball of my foot.

For the sheet steel, I used the bottom of a large size metal coffee can, used a tin snips which is a very heavy duty scissors for the purpose of cutting sheet metal. (Many people do not own a tin snips, I am one of the lucky ones that does.)

Unfortunately, Keen no longer makes cycling shoes or sandals. I am very happy with mine, fit my wide feet great.