If you turn on Set IK/FK Keys in the options window for Animate > Set Key >  , you can subsequently use Animate > Set Key as an alternative to Animate > IK/FK Keys > Set IK/FK Key.
, you can subsequently use Animate > Set Key as an alternative to Animate > IK/FK Keys > Set IK/FK Key. 
         
If you use Animate > Set Key for an object that’s not an IK handle, a joint controlled by an IK handle, or an object connected to an IK handle, the Set IK/FK Keys option is ignored.