My 2009 27-inch iMac still runs great! And for its time, it was a great Photoshop workstation.
The 2010 iMac will run macOS Mountain Lion 10.8.5 to macOS High Sierra 10.13.6. If you have the stand-alone installer and your serial number for an older Photoshop (like CS6 for example), it may install but probably will not activate. So, unfortunately, a 2010 iMac is too old.