Getting locked out of your house is the worst. Having a hide-a-key can help, but you need to make sure it doesn't look too conspicuous. This setup looks just like some plain old piping on the side of the house.
In this video, the HouseholdHacker YouTube channel shows you how to creatively disguise your house key in plain sight, and for fairly cheap. Once you have the PVC piping and other supplies suggested in the video, dig a hole out by the side of your house — or maybe even in your backyard — and set it up so it looks like some piping that goes into the side of your house. Just make sure it's all flush, or it will look pretty obvious.
Check out the link below to get a complete list of the materials you need. If this setup doesn't work you, there's always a great way to reuse an old medicine bottle.