Select query with nested relationships
You could use EXISTS instead of IN. That's likely to perform better.

SELECT *
       FROM "wallet"
            LEFT JOIN "amount"
                      ON "wallet"."id" = "amount"."walletId"
                         AND EXISTS (SELECT *
                                            FROM "order"
                                            WHERE "order"."id" = "amount"."orderId"
                                                  AND "order"."status" IN ('new',
                                                                           'accepted'))
       WHERE "wallet"."locked" = false;


To further improve the performance of the above maybe try indexes on "wallet" ("locked", "id"), "amount" ("walletid", "orderid") and order ("id", "status"). Unless you have them already, of course.

Check the plan if you're unsure which version performs better and what indexes help.