I think the keyframe indicator in the Motion tab of the Viewer is pretty horrible. It's buggy, has scaling problems and is generally trickier to use than it should be so here's a tiny bit of help.
When you set some keyframes, and you have Wireframe + Image on in the Canvas (toggle it with "w") relevant parts of the wireframe will turn green to indicate that they have a keyframe and that the playhead is currently on their keyframe.
In the above image you can see that among the green there are some white indicators, namely the "1" and the upper left and lower right handles. Here's what the Basic Motion tab looks like for this shot of clouds:
You can see that Scale, Center, Upper Right and Lower Left all have keyframes. Scale is the large X-like crossing lines, Center is the center handle and the upper right and lower left handles are right where they should be. If the "1" were green, that would mean that the playhead is on a Anchor Point keyframe.