SELECT page_title

FROM page AS p1

LEFT JOIN redirect r1 ON r1.rd_from = p1.page_id

WHERE p1.page_namespace = 0

  AND p1.page_title RLIKE '(?i)(2020_(Summer_)?(O|Para)lympics|Tokyo_2020)'

  AND p1.page_is_redirect = 1

  AND NOT EXISTS (SELECT 1 FROM redirect

                  LEFT JOIN page AS p2 ON p2.page_id = rd_from

                  WHERE rd_namespace = r1.rd_namespace

                    AND rd_title = r1.page_title

                    AND p2.page_namespace = 0

                    AND p2.page_namespace = REPLACE(p1.page_title, '2020', '2021'));