Elasticsearch and product characteristics

Question

I have a small question about elasticsearch. Let's say I have a database with products to sell, like an ecommerce.

I know that elasticsearch can help me to find the best product with, for instance a full text search on the description and sorting by score.

Let's say someone is looking for sport shoes, and I don't sell any, but I do sell shoes. What would be the best way to show the user I don't have any? The full text search will for sure give me everyday shoes in the results, since the word "shoes" is in the query, but I would prefer the user to know I don't sell any rather than seeing products that don't match his query.

Is it as simple as setting a score threshold and playing with it until having good results, or are there specific settings?

I'm also interested in generic answers having nothing to do with elasticsearch.

Thanks a lot!