The description you provided—"a story that takes place in the real world, usually in present times"—only partially encapsulates the essence of a mystery.
A better definition of a mystery would be: a narrative that revolves around the investigation of a crime or an event that is difficult to understand or explain, typically involving a puzzle or enigma that needs to be solved. Mysteries often feature detectives or amateur sleuths who work to uncover hidden truths, reveal secrets, and piece together clues.
Therefore, while your description aligns with some aspects of the genre, it lacks the emphasis on the elements of intrigue, investigation, and resolution central to mystery stories.