Yes, that is someone’s foot touching a moving lava flow without combusting.

It’s a screenshot from this video – notice the person just lightly taps the foot, because this lava with unusual chemistry is still pretty hot. Still, you can get close, unlike around a runny red Hawaiian lava flow.

Be sure your speakers are on when you watch this snap-crackle-and-pop volcano in action.

Here is Ol Doinyo Lengai’s Global Volcanism Program page from the Smithsonian.