DELETE * FROM t1 JOIN t2 WHERE t1.c1=0 OR (t1.c2=t2.c1 AND t2.c3=3)

DELETE FROM t1 WHERE t1.c1=0 OR EXISTS (SELECT 1 FROM t2 WHERE t1.c2=t2.c1 AND t2.c3=3)

DELETE * FROM t1 JOIN t2 WHERE t1.c1=0 OR t1.c2=t2.c1 AND t2.c3=3

DELETE FROM t1 WHERE t1.id IN (SELECT id
                                     FROM t1
                                     INNER JOIN t2 u on t1.id_externo = t1.id
                                   WHERE COLOCA TU CONDICION AQUI)

DELETE FROM t1 WHERE t1.id IN (CONSULTA) OR t1.id IN (CONSULTA)