jak zrychlit fulltextové vyhledávání

SELECT *
                FROM clanek C 
                JOIN region_portal ON portal_clanek_en = nazev_portal_en
                JOIN foto_clanek FC ON C.id_clanek = FC.id_clanek
                WHERE aktivni = 1 
                AND aktivni_od < NOW() 
                AND aktivni_do > NOW() 
                AND  
                (
                     MATCH(nazev_clanek)   AGAINST ('volny-cas*' IN BOOLEAN MODE) OR 
                     MATCH(anotace_clanek) AGAINST ('volny-cas*' IN BOOLEAN MODE) OR 
                     MATCH(text)           AGAINST ('volny-cas*' IN BOOLEAN MODE)
                ) 
                GROUP BY C.id_clanek
                ORDER BY 10*MATCH(nazev_clanek) AGAINST ('volny-cas*' IN BOOLEAN MODE) DESC