How to Design a Table for scoring system in Cassandra?

I have a table for my products in Cassandra. In this table I store the product name and seller name (there may be thousands of sellers) and score (Product score of the seller) so as following

CREATE TABLE products (     product_name varchar,     seller_name varchar,     score    int,     primary key (product_name, seller_name) ); 

I need to update score in my code

UPDATE products SET score = 2 WHERE product_name = "iphone-7" AND seller_name = "jack" ; 

Everything is fine, except for Select Query:

SELECT * FROM products WHERE product_name = "iphone-7" ORDER BY SCORE DESC; 

I need to get products by score order But as you know, it is not possible to sort without score being the primary key But if I put the score in the primary key, it will be not possible to update it what’s the solution?