SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    100751, 100752, 100753, 100754, 100755, 
    100756, 100757, 100758, 100759, 100760, 
    100761, 100762, 100763, 100764, 100765, 
    100766, 100767, 100768, 100769, 100770, 
    100771, 100772, 100773, 100774, 100775, 
    100776, 100777, 100778, 100779, 100780, 
    100781, 100782, 100783, 100784, 100785, 
    100786, 100787, 100788, 100789, 100790, 
    100791, 100792, 100793, 100794, 100795, 
    100796, 100797, 100798, 100799, 100800, 
    100801, 100802, 100803, 100804, 100805, 
    100806, 100807, 100808, 100809, 100810, 
    100811, 100812, 100813, 100814, 100815, 
    100816, 100817, 100818, 100819, 100820, 
    100821, 100822, 100823, 100824, 100825, 
    100826, 100827, 100828, 100829, 100830, 
    100831, 100832, 100833, 100834, 100835, 
    100836, 100837, 100838, 100839, 100840, 
    100841, 100842, 100843, 100844, 100845, 
    100846
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00148

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.24"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 96,
      "rows_produced_per_join": 96,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "33.64",
        "eval_cost": "9.60",
        "prefix_cost": "43.24",
        "data_read_per_join": "366K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (100751,100752,100753,100754,100755,100756,100757,100758,100759,100760,100761,100762,100763,100764,100765,100766,100767,100768,100769,100770,100771,100772,100773,100774,100775,100776,100777,100778,100779,100780,100781,100782,100783,100784,100785,100786,100787,100788,100789,100790,100791,100792,100793,100794,100795,100796,100797,100798,100799,100800,100801,100802,100803,100804,100805,100806,100807,100808,100809,100810,100811,100812,100813,100814,100815,100816,100817,100818,100819,100820,100821,100822,100823,100824,100825,100826,100827,100828,100829,100830,100831,100832,100833,100834,100835,100836,100837,100838,100839,100840,100841,100842,100843,100844,100845,100846)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}