Both Daktarin and maisil are good, and boots do good own brand products.
The other thing to remember is the fungal infection that causes Athletes foot, lives in the damp in your shoes..
So if you suffer from it, NEVER wear the same shoes 2 days running, as the sweat from your feet will not have dried, and you will just keep reinfecting yourself.
Alternate between pairs of shoes, making sure they are thoroughly dry before you wear them again. Also worth buying an athletes foot treatment spray, and giving your shoes a regualar squirt with it once you take them off.
If like me, you have a habit of scratching your feet in the night, or rubbing them against the sheets while you are asleep, you should probably wear cotton socks overnight till it clears up to prevent the scratching, and preferably put some powder treatment in the sock before you put it on.
Good luck.