1st recommendation:
Get only visible details and properties of a node in python - Coding / Python Support - Blender Artists Community
Enabling feedback to show what the python commands are for most items (in your specific example this got you to the:
bpy.data.actions[“CubeAction.008”].(null) point of the code.
2nd recommendation:
Just spending time using commands in the console.
since you know your keyframe is an fcurve try to find it in the object data block
3rd recommendation:
Continue to search and post on forums. Given Blenders’s increasing user base; someone somewhere is bound to have either stumbled there way through it previously, or just be too stubborn a person to not know themselves and fumble through an answer.