The idea of the tombs of Pharaoh's being cursed is a fairly modern one. The tombs themselves bear no hieroglyphic markings to this effect. Desecrating a pharaoh's resting place would have been an incredible blasphemy, of course, but soldiers would have executed anyone who even tried. Supernatural curses really became part of the folklore during the Egyptology craze of the Victorian Era, and were widely publicized after the discovery of Tutankhamun's final resting place in 1922. While it's a relatively modern idea it's also a fairly short-lived one in terms of people taking it seriously, and by Ellery Queen's late 1940's setting it would be considered a joke.
And while detective fiction does have a certain basis in fantasy, detective fiction with supernatural events is a more specialized field. Doyle's Sherlock Holmes, Chesterton's Father Brown, and John Dickson Carr's Gideon Fell (a Chesterton tribute) all came across crimes that seemed like they might be spectral but generally had a naturalistic explanation. William Hope Hodgson frequently found evidence of actual supernatural involvement. But Ellery Queen's mysteries in all media had little to do with the first kind of story, and never went near the second.
So it's not too much of a surprise that, despite the title, there's no curse in this episode. There's not even much of a fake-out. The victim, wealthy aviation mogul and amateur archaeologist Norris Wentworth, has a heart condition, giving his death a perfectly mundane explanation. Nobody gives much credence to the curse and very few think murder is likely either, despite Wentworth being kind of a bastard and making the requisite number of enemies. In fact in this case there's actually some doubt about whether it is murder properly speaking even after the culprit has been found out and confessed.
The one person who does speak about the pharaoh getting revenge is an Egyptian national who storms into the museum to protest the exhibit. He might simply be feigning belief. Demographically he'd be likely to be a Muslim or Christian, neither of whom would worship Egyptian deities. His anger at his country's exploitation by profiteers like Wentworth is sincere, though. The fact that the show takes him seriously is good, though, especially since negative stereotypes about Middle Easterners had intensified in the wake of the Six-Day War and there weren't a lot of sympathetic portrayals.
For the second consecutive time, Simon Brimmer appears before Ellery Queen or his dad. Actually it's several minutes before we see any of the regulars. Simon consults with Wentworth before his death because he's interested in working the tomb and six previous deaths associated with it into his show. Wentworth himself makes seven, of course, which moves up the plans. He and Ellery are the only two characters who really believe the death is anything but natural causes, so they wind up working together, making a pretty effective team.
Ellery is more distracted than usual because he's writing a novel on a deadline. To get it finished he's working with a steno because he sliced his hand on a can opener. This element made me wonder if Jim Hutton had a hand injury in real life and they needed to account for the bandages.
William Link himself later criticized the episode's solution as being too obscure, saying that he and Richard Levinson were determined to keep things simpler when they created Murder, She Wrote several years later. In fairness, the keyring was shown before the denouement, in a way that hinted it could be significant. There are some other elements that either weren't shown or not emphasized, but in either case the audience can't really be expected to remember them. Say that as a mystery this one dances out on the edges of fair play.
As 40-50 minutes of entertainment, however, it's very brisk. The dynamics between Ellery, Inspector Queen, and Simon are solid. We're at the rough halfway point of Ellery Queen and it's got a very good track record.