How can I create this effect in After Effects, that small glow?

Maybe try the tritone effect or just the tint effect then keyframe its blend with original property.  Start at 100%, then set it to 60%, then back to 100%.  You can then select all the keyframes, right-click and choose Keyframe assistant… Easy Ease.

There is also the glow effect, but that screenshot look more subtle than regular glows, and more like a tint.

Hi,
for a clean and controllable glow like in your reference images, I’d recommend using a dedicated glow plugin rather than the built-in Glow effect. Personally, I like Deep Glow a lot because it produces a more natural falloff and doesn’t clip highlights as aggressively.

The basic idea is to keep the object normal at first, then animate the glow intensity over time using keyframes or an expression, and ease it in and out so the glow appears and fades smoothly. With Deep Glow, this is very straightforward since you can keyframe the intensity and spread independently.

If you want to do it without plugins, you can stack multiple native Glow effects and animate the threshold and intensity, but it usually takes more tweaking to get a soft, realistic result.

I also make After Effects tutorials and share presets focused on clean, efficient workflows, so feel free to check out my profile if you’re interested. ​@Lossvisuals. 

post in the after effects forum.