The Card Key was a mythical item in Pokemon GO that was never actually released. It was often rumored to be found at the Silph Co. building because the building itself is a real-life landmark associated with Pokemon lore.
There are a few reasons why people believe the Card Key is at the Silph Co.:
* Early Game Rumors: In the early days of Pokemon GO, there were rumors and speculation about the Card Key and its location. The Silph Co. became a popular place for players to gather and discuss the game, making it a logical focal point for the rumor.
* In-Game References: The Silph Co. building is mentioned in the game's lore and has a small role in some events.
* Fan Fiction and Theories: The mystery surrounding the Card Key fueled a lot of fan fiction and theories, often involving the Silph Co. building.
However, Niantic, the developers of Pokemon GO, have never confirmed the existence of the Card Key, and it has never been released in the game.
So, to answer your question directly: There is no Card Key in Pokemon GO, and it is not located at the Silph Co. building in New York City.