It could be used while talking in the present tense, which people rarely do. Think telling a story. For example: "I walk down to the corner store. There are a few other customers in line so it is a while before I can get the cashier's attention."
The drop down translation highlights "un rato" as a compound word group meaning "for a while". I am wondering if this is ever so, or is there other forces that must be in play before "un rato" means "for a while".