The optimization process and recommendations:

1. Avoid Subqueries (query line: 7): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
2. 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.
3. Sort and Limit Before Joining (modified query below): In cases where the joins aren't filtering any rows, it's possible to sort and limit the amount of rows using a subquery in the FROM clause, before applying the joins to all other tables.

Optimal indexes for this query:

ALTER TABLE `record` ADD INDEX `record_idx_file_id_status_id` (`file_group_id`,`status_id`);
ALTER TABLE `record_meta_text` ADD INDEX `record_text_idx_column_id_record_id` (`column_id`,`record_id`);

The optimized query:

SELECT
        col_title AS col_title,
        rmt_2780.value AS col_2780,
        rmt_2781.value AS col_2781,
        rmt_18474.value AS col_18474 
    FROM
        (SELECT
            r.title AS col_title,
            r.id AS r_id 
        FROM
            record r 
        WHERE
            r.file_group_id = 2350 
            AND r.status_id = 1 LIMIT 50) r 
    INNER JOIN
        record_meta_text AS rmt_2780 
            ON rmt_2780.record_id = r.r_id 
            AND rmt_2780.column_id = 2780 
    INNER JOIN
        record_meta_text AS rmt_2781 
            ON rmt_2781.record_id = r.r_id 
            AND rmt_2781.column_id = 2781 
    INNER JOIN
        record_meta_text AS rmt_18474 
            ON rmt_18474.record_id = r.r_id 
            AND rmt_18474.column_id = 18474 
    WHERE
        1 = 1 
        AND 1 = 1 LIMIT 50