Multiple Update with Multiple Conditions
In MySQL, you can use tuple comparison:

WHERE (TestId, TestSubId) IN ((10,25), (11,22))


That looks nice and succinct, although, as ypercubeᵀᴹ mentioned in a comment, it may not work well performance-wise.

However, given how the conditions are re-used in your UPDATE statement, you could also take a different approach altogether: represent the affected IDs and the new values as a derived table and use an update with a join:

UPDATE
    Tests AS old
    INNER JOIN
    (
        SELECT 10 AS TestId, 25 AS TestSubId, 1000 AS TestScore, 2000 AS TestScore2
        UNION ALL
        SELECT 11, 22, 1100, 2100
    ) AS new
    ON old.TestId = new.TestId AND old.TestSubId = new.TestSubId
SET
    old.TestScore  = new.TestScore,
    old.TestScore2 = new.TestScore2
;


This way the new derived table acts both as a filter for Tests and a supplier of new values for the update.