The optimization process and recommendations:

1. Avoid Correlated Subqueries In Select Clause (modified query below): The aggregation function located in a subquery inside the SELECT clause, is executed once for every matched row. Extracting this subquery to a temporary table will improve performance significantly.
2. Avoid Selecting Unnecessary Columns (query line: 2): Avoid selecting all columns with the '*' wildcard, unless you intend to use them all. Selecting redundant columns may result in unnecessary performance degradation.
3. 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.
4. Replace In Subquery With Correlated Exists (modified query below): In many cases, an EXISTS subquery with a correlated condition will perform better than a non correlated IN subquery.

Optimal indexes for this query:

ALTER TABLE `event` ADD INDEX `event_idx_event_id` (`event_id`);
ALTER TABLE `schedule` ADD INDEX `schedule_idx_schedule_id_event_id` (`schedule_id`,`event_id`);
ALTER TABLE `team` ADD INDEX `team_idx_schedule_id` (`schedule_id`);

The optimized query:

SELECT
        * 
    FROM
        team 
    WHERE
        EXISTS (
            SELECT
                1 
            FROM
                (SELECT
                    team.team_id,
                    es_temp1.members 
                FROM
                    team,
                    schedule,
                    event 
                LEFT JOIN
                    es_temp1 
                        ON es_temp1.team_id = team.team_id 
                WHERE
                    team.schedule_id = schedule.schedule_id 
                    AND schedule.event_id = event.event_id 
                    AND event.event_id = 183) AS t 
            WHERE
                (
                    members = 0
                ) 
                AND (
                    team.team_id = t.team_id
                )
            )