Thor is still a prisoner of Zarrko the Tomorrow Man, who's brought the Thunder God to the 23rd Century to help him conquer that peaceful century.
Thor, who promised Zarrko obedience to get him to leave the 20th Century alone, goes on a rampage. Fortunately, he's able to subdue the inhabitants of the future century for the most part by merely destroying machines and robots. He's never obligated to actually hurt anyone, though he does reflect light off his hammer in such a way to place some human guards in a trance.
It actually might have been a stronger issue if it had presented Thor with a real moral dilemma. If--as Thor tells us at one point--"an immortal may never break an oath," then what happens if keeping the oath requires doing something immoral?
But the story never puts Thor in that position. And, when the world surrenders to Zarrko, Thor is able to consider his oath fulfilled. He fights Zarrko and defeats him, saving the 23rd Century from despotism.
Oh, well. The story might have missed an opportunity to do something really challenging, but Jack Kirby's futuristic city scapes and machinary are cool-looking.
And his work on the "Tales of Asgard" entry is even cooler-looking. Young Thor is still trying to become worthy of wielding his hammer. But when he finds out the innocent goddess Sif has been taken captive by Hela, the Goddess of Death, he picks up the weapon without even thinking about it. Soon, he's offering Hela his own life in place of Sif's, proving himself very worthy indeed.
CORRECTION: This version of Scarecrow is indeed the supernatural guy who appeared in later years, not a different character as I stated above. I was also wrong about the later version of Scarecrow being inter-dimensional. Actually, he eventually gets raised as an undead being by a sorceror. My apologies for the factual errors.