Original query:

SELECT
    id
FROM
    "appointments"
WHERE
    "agenda_id" IN (3943, 5699, 1525, 4006, 3221, 2858, 1528, 1514, 4967, 5698, 5452, 5969, 2147, 1512, 5453)
    AND ("start_at" <= '2019-01-14T00:00:00.000+00:00'
        AND "end_at" >= '2019-01-01T00:00:00.000+00:00')