SELECT 
  a.variant_id, 
  a.option_id, 
  a.position, 
  a.modifier, 
  a.modifier_type, 
  a.weight_modifier, 
  a.weight_modifier_type, 
  b.variant_name, 
  IF(
    shared_option_variants.variant_id IS NOT NULL, 
    shared_option_variants.modifier, 
    a.modifier
  ) as modifier, 
  IF(
    shared_option_variants.variant_id IS NOT NULL, 
    shared_option_variants.modifier_type, 
    a.modifier_type
  ) as modifier_type 
FROM 
  cscart_product_option_variants as a 
  LEFT JOIN cscart_product_option_variants_descriptions as b ON a.variant_id = b.variant_id 
  AND b.lang_code = 'en' 
  LEFT JOIN cscart_ult_product_option_variants shared_option_variants ON shared_option_variants.variant_id = a.variant_id 
  AND shared_option_variants.company_id = 2 
WHERE 
  a.option_id IN (990, 1323, 1322, 1165, 1198, 1149) 
  AND a.status = 'A' 
ORDER BY 
  a.position, 
  a.variant_id

Query time 0.00093

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE a range status,option_id,option_id_2 option_id 6 57 Using index condition; Using filesort
1 SIMPLE b eq_ref PRIMARY PRIMARY 9 mahm3t_cs443.a.variant_id,const 1 Using where
1 SIMPLE shared_option_variants eq_ref PRIMARY,company_id PRIMARY 7 mahm3t_cs443.a.variant_id,const 1

Result

variant_id option_id position modifier modifier_type weight_modifier weight_modifier_type variant_name
24005 1323 0 0.000 A 0.000 A TFX | for tiles up to 50mm in profile
24007 1323 5 0.000 A 0.000 A LSX | for slate up to 16mm thick
24009 1323 50 0.000 A 0.000 A UCX13 | for kombi - 2 windows side by side
19576 990 120 0.000 A 0.000 A C2A | 55x78 cm
23997 1322 120 0.000 A 0.000 A C2A | 55x78 cm
19578 990 140 0.000 A 0.000 A C4A | 55x98 cm
23998 1322 140 0.000 A 0.000 A C4A | 55x98 cm
19579 990 360 0.000 A 0.000 A F6A | 66x118 cm
23999 1322 360 0.000 A 0.000 A F6A | 66x118 cm
22118 1165 507 0.000 A 0.000 A C2A
22119 1165 509 0.000 A 0.000 A C4A
19580 990 540 0.000 A 0.000 A M4A | 78x98 cm
24000 1322 540 0.000 A 0.000 A M4A | 78x98 cm
19581 990 560 0.000 A 0.000 A M6A | 78x118 cm
24001 1322 560 0.000 A 0.000 A M6A | 78x118 cm
19582 990 580 0.000 A 0.000 A M8A | 78x140 cm
24002 1322 580 0.000 A 0.000 A M8A | 78x140 cm
22120 1165 609 0.000 A 0.000 A F4A
22121 1165 611 0.000 A 0.000 A F6A
22122 1165 709 0.000 A 0.000 A M4A
22123 1165 711 0.000 A 0.000 A M6A
22124 1165 714 0.000 A 0.000 A M8A
22125 1165 716 0.000 A 0.000 A M10A
19577 990 760 0.000 A 0.000 A S6A | 114x118 cm
24003 1322 760 0.000 A 0.000 A S6A | 114x118 cm
22126 1165 911 0.000 A 0.000 A P6A
22506 1165 914 0.000 A 0.000 A P8A
22127 1165 1111 0.000 A 0.000 A S6A
22128 1165 1114 0.000 A 0.000 A S8A
22129 1165 1309 0.000 A 0.000 A U4A
22507 1198 4208 0.000 A 0.000 A White
22508 1198 4212 0.000 A 0.000 A Dark blue
22510 1198 4217 0.000 A 0.000 A Graphite
22511 1198 4219 0.000 A 0.000 A Beige
24197 1198 5204 0.000 A 0.000 A Light grey