It will affect the speed of filtering on a "title" field. For example, if you want to introduce some combinations of vector and keyword search, aka you have some keyword (brand name) in a title, and you want to filter it with Qdrant's filtering mechanisms, it makes sense to index the payload field. (more here: https://qdrant.tech/articles/vector-search-filtering/)

Indexing the payload field won't affect the speed of vector search, though, which you're performing now, as I got it:)