Re: Index Not being used.

[Rick James]

Please provide SHOW CREATE TABLE for each table.
Please provide SHOW VARIABLES LIKE '%buffer%';
How much RAM do you have?
Please provide SHOW TABLE STATUS;

These will provide info on whether the caching is part of the problem and whether you have the requisite indexes and how big the tables are.
From that, we can discuss where you need more indexes, especially composite indexes, and whether you need to change some cache sizes.