(1) Notwithstanding any other provision of law, any civil action challenging the constitutionality of section
534 or
535 of this title or any provision thereof shall be heard by a district court of three judges convened pursuant to the provisions of section
2284 of title
28.
(2) Notwithstanding any other provision of law, an interlocutory or final judgment, decree, or order of the court of three judges in an action under paragraph (1) holding section
534 or
535 of this title or any provision thereof unconstitutional shall be reviewable as a matter of right by direct appeal to the Supreme Court. Any such appeal shall be filed not more than 20 days after entry of such judgment, decree, or order.