The optimization process and recommendations:

1. Avoid Subqueries (query line: 25): 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.

Optimal indexes for this query:

ALTER TABLE `Events` ADD INDEX `events_idx_eventid` (`EventId`);
ALTER TABLE `Races` ADD INDEX `races_idx_event` (`Event`);

The optimized query:

SELECT
        TOP 3 Id2_1_,
        RaceId2_1_,
        Year2_1_,
        IsValid2_1_,
        Time2_1_,
        Event2_1_,
        Id1_0_,
        EventId1_0_ 
    FROM
        (SELECT
            ROW_NUMBER() OVER (ORDER 
        BY
            __hibernate_sort_expr_0__ DESC) AS row,
            query.Id2_1_,
            query.RaceId2_1_,
            query.Year2_1_,
            query.IsValid2_1_,
            query.Time2_1_,
            query.Event2_1_,
            query.Id1_0_,
            query.EventId1_0_,
            query.__hibernate_sort_expr_0__ 
        FROM
            (SELECT
                this_.Id AS Id2_1_,
                this_.RaceId AS RaceId2_1_,
                this_.Year AS Year2_1_,
                this_.IsValid AS IsValid2_1_,
                this_.Time AS Time2_1_,
                this_.Event AS Event2_1_,
                event1_.Id AS Id1_0_,
                event1_.EventId AS EventId1_0_,
                this_.Time AS __hibernate_sort_expr_0__ 
            FROM
                Races this_ 
            INNER JOIN
                Events event1_ 
                    ON this_.Event = event1_.Id 
            WHERE
                event1_.EventId = @p0) query) page 
        WHERE
            page.row > 0 
        ORDER BY
            __hibernate_sort_expr_0__ DESC