Keyword indexing can take as little as a few minutes to as long as a few days. Generally, we see complete indexation with a few hours of adding the new copy. Once your keywords are indexed, you may find your product ranking well for long-tail low competition keywords with little to no sales, but for more competitive keywords, you will have to do more to prove your relevance. The best way to prove relevance is through sales! Make sure that your listing is well optimized before driving sales or you will never find your product ranking.