The optimization process and recommendations:

1. Create Optimal Indexes (modified query below): The recommended indexes are an integral part of this optimization effort and should be created before testing the execution duration of the optimized query.
2. Prefer Inner Join Over Left Join (modified query below): We identified that one or more left joined entities (e.g. `wp_terms`) are used in the 'where' clause, in a way that allows to replace it with an optimized inner join. Inner joins can be fully optimized by the database, while Left joins apply limitations on the database's optimizer.

Optimal indexes for this query:

ALTER TABLE `wp_posts` ADD INDEX `wp_posts_idx_id` (`ID`);
ALTER TABLE `wp_term_relationships` ADD INDEX `wp_relationships_idx_term_id` (`term_taxonomy_id`);
ALTER TABLE `wp_term_taxonomy` ADD INDEX `wp_taxonomy_idx_term_id` (`term_id`);
ALTER TABLE `wp_terms` ADD INDEX `wp_terms_idx_term_id` (`term_id`);

The optimized query:

SELECT
        COUNT(*) 
    FROM
        wp_posts 
    LEFT JOIN
        wp_term_relationships 
            ON wp_posts.ID = wp_term_relationships.object_id 
    LEFT JOIN
        wp_term_taxonomy 
            ON wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id 
    INNER JOIN
        wp_terms 
            ON wp_term_taxonomy.term_id = wp_terms.term_id 
    WHERE
        wp_terms.term_id = 195