get->id: 1
Category query with limit:
SELECT t1.id, t1.primaran, t1.naziv, t1.mpcena, t1.ascase FROM ( SELECT a.id,a.primaran,a.naziv,a.mpcena,CASE WHEN a.sifra='OPL03WH150110C' THEN 0 WHEN a.sifra='OPL04WH150110C' THEN 1 WHEN a.sifra='OPO01BK029042C' THEN 2 WHEN a.sifra='OPO06BK040032C' THEN 3 WHEN a.sifra='OPL09BK150110C' THEN 4 WHEN a.sifra='OPL08BK150110C' THEN 5 WHEN a.sifra='OPO07BK040047C' THEN 6 WHEN a.sifra='OPL03BK082051C' THEN 7 WHEN a.sifra='OPL10BK090076C' THEN 8 WHEN a.sifra='OPL08BK300137C' THEN 9 ELSE 10 END as ascase FROM `artikli` a LEFT JOIN categories c ON c.id=a.category_id INNER JOIN artikli2category a2c ON a.`id` = a2c.`id_artikla` WHERE a.`id`!='0' AND a.`novo`!='on' AND a.`aktivan`='on' AND a.prikaz_b2c='on' AND a.`mpcena`!='0.00' AND a2c.category_id IN (1,3,4,5,6,7,8,9,74,76,14,15,16,39,40,41,42,45,46,51,57,58,88,89,91,101,102,103,104,121,132,133,134,135,136,137,122) UNION SELECT a.id,a.primaran,a.naziv,a.mpcena,CASE WHEN a.sifra='OPL03WH150110C' THEN 0 WHEN a.sifra='OPL04WH150110C' THEN 1 WHEN a.sifra='OPO01BK029042C' THEN 2 WHEN a.sifra='OPO06BK040032C' THEN 3 WHEN a.sifra='OPL09BK150110C' THEN 4 WHEN a.sifra='OPL08BK150110C' THEN 5 WHEN a.sifra='OPO07BK040047C' THEN 6 WHEN a.sifra='OPL03BK082051C' THEN 7 WHEN a.sifra='OPL10BK090076C' THEN 8 WHEN a.sifra='OPL08BK300137C' THEN 9 ELSE 10 END as ascase FROM `artikli` a LEFT JOIN categories c ON c.id=a.category_id INNER JOIN artikli2category a2c ON a.`id` = a2c.`id_artikla` WHERE a.`id`!='0' AND a.`novo`!='on' AND a.`aktivan`='on' AND a.prikaz_b2c='on' AND a.`mpcena`!='0.00' AND a2c.category_id IN (1,3,4,5,6,7,8,9,74,76,14,15,16,39,40,41,42,45,46,51,57,58,88,89,91,101,102,103,104,121,132,133,134,135,136,137,122) AND a.vodi_se_zaliha='' ) t1 ORDER BY ascase ASC, `id` DESC LIMIT 0, 24

Category query all:
SELECT t1.id, t1.primaran, t1.naziv, t1.mpcena, t1.ascase FROM ( SELECT a.id,a.primaran,a.naziv,a.mpcena,CASE WHEN a.sifra='OPL03WH150110C' THEN 0 WHEN a.sifra='OPL04WH150110C' THEN 1 WHEN a.sifra='OPO01BK029042C' THEN 2 WHEN a.sifra='OPO06BK040032C' THEN 3 WHEN a.sifra='OPL09BK150110C' THEN 4 WHEN a.sifra='OPL08BK150110C' THEN 5 WHEN a.sifra='OPO07BK040047C' THEN 6 WHEN a.sifra='OPL03BK082051C' THEN 7 WHEN a.sifra='OPL10BK090076C' THEN 8 WHEN a.sifra='OPL08BK300137C' THEN 9 ELSE 10 END as ascase FROM `artikli` a LEFT JOIN categories c ON c.id=a.category_id INNER JOIN artikli2category a2c ON a.`id` = a2c.`id_artikla` WHERE a.`id`!='0' AND a.`novo`!='on' AND a.`aktivan`='on' AND a.prikaz_b2c='on' AND a.`mpcena`!='0.00' AND a2c.category_id IN (1,3,4,5,6,7,8,9,74,76,14,15,16,39,40,41,42,45,46,51,57,58,88,89,91,101,102,103,104,121,132,133,134,135,136,137,122) UNION SELECT a.id,a.primaran,a.naziv,a.mpcena,CASE WHEN a.sifra='OPL03WH150110C' THEN 0 WHEN a.sifra='OPL04WH150110C' THEN 1 WHEN a.sifra='OPO01BK029042C' THEN 2 WHEN a.sifra='OPO06BK040032C' THEN 3 WHEN a.sifra='OPL09BK150110C' THEN 4 WHEN a.sifra='OPL08BK150110C' THEN 5 WHEN a.sifra='OPO07BK040047C' THEN 6 WHEN a.sifra='OPL03BK082051C' THEN 7 WHEN a.sifra='OPL10BK090076C' THEN 8 WHEN a.sifra='OPL08BK300137C' THEN 9 ELSE 10 END as ascase FROM `artikli` a LEFT JOIN categories c ON c.id=a.category_id INNER JOIN artikli2category a2c ON a.`id` = a2c.`id_artikla` WHERE a.`id`!='0' AND a.`novo`!='on' AND a.`aktivan`='on' AND a.prikaz_b2c='on' AND a.`mpcena`!='0.00' AND a2c.category_id IN (1,3,4,5,6,7,8,9,74,76,14,15,16,39,40,41,42,45,46,51,57,58,88,89,91,101,102,103,104,121,132,133,134,135,136,137,122) AND a.vodi_se_zaliha='' ) t1 ORDER BY ascase ASC, `id` DESC