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 (
    84716, 84738, 92171, 84726, 84742, 84935, 
    84858, 92175, 84740, 84942, 84934, 
    92167, 84737, 84739, 84725, 87980, 
    87983, 84741, 87984, 87970, 88023, 
    84947, 88032, 87985, 84736, 84688, 
    87979, 84960, 87978, 84850, 84743, 
    84849, 84951, 84747, 84761, 84717, 
    87969, 84846, 85274, 88022, 88017, 
    93158, 93159, 93797, 94450, 94796, 
    94797, 94802, 94803, 94807, 94808, 
    94826, 94842, 95555, 95738, 95739, 
    95740, 95741, 95742, 95754, 95819, 
    96529, 98416, 99139, 99140, 99148, 
    99149, 99150, 99156, 99157, 99159, 
    99160, 99161, 99196, 99201, 99210, 
    99211
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00154

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "34.68"
    },
    "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": 77,
      "rows_produced_per_join": 77,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "26.99",
        "eval_cost": "7.70",
        "prefix_cost": "34.69",
        "data_read_per_join": "293K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (84716,84738,92171,84726,84742,84935,84858,92175,84740,84942,84934,92167,84737,84739,84725,87980,87983,84741,87984,87970,88023,84947,88032,87985,84736,84688,87979,84960,87978,84850,84743,84849,84951,84747,84761,84717,87969,84846,85274,88022,88017,93158,93159,93797,94450,94796,94797,94802,94803,94807,94808,94826,94842,95555,95738,95739,95740,95741,95742,95754,95819,96529,98416,99139,99140,99148,99149,99150,99156,99157,99159,99160,99161,99196,99201,99210,99211)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
84688 nuie Bliss Semi Flush to Wall WC
84716 Hudson Reed Maya Flush to Wall Pan, Cistern & Seat
84717 Old London Richmond Close Coupled Pan & Cistern
84725 Old London Richmond Low Level Pan, Cistern & Flush Pipe Kit
84726 Old London Richmond High Level Pan, Cistern & Flush Pipe Kit
84736 Old London Richmond Comfort Height Close Coupled WC & Cistern
84737 Old London Richmond Comfort Height Low Level WC & Flush Pipe
84738 Old London Richmond Comfort Height High Level WC & Flush Pipe
84739 Old London Richmond Mid Level Pan, Cistern and Flush Pipe Kit
84740 Old London Richmond Comfort Height Mid Level Pan, Cistern and Flush Pipe Kit
84741 nuie Carlton Low Level Pan, Cistern & Flush Pipe Kit
84742 nuie Carlton High Level Pan, Cistern & Flush Pipe Kit
84743 nuie Carlton Close Coupled Pan Cistern & Seat
84747 nuie Harmony Pan & Cistern
84761 nuie Provost Semi Flush to Wall WC
84846 nuie Legend Close Coupled WC
84849 nuie Lawton Compact Pan & Cistern
84850 nuie Lawton Close Coupled WC
84858 Hudson Reed Luna Flush to Wall Pan, Cistern & Seat
84934 Hudson Reed Arlo Flush to Wall Pan, Cistern & Seat
84935 nuie Ambrose Compact Semi Flush to Wall WC
84942 Hudson Reed Arlo Compact Flush to Wall Pan, Cistern & Seat
84947 nuie Provost Semi Flush to Wall WC
84951 Old London Chancery Close Coupled Pan & Cistern
84960 nuie Asselby Close Coupled WC
85274 nuie Doc M Pack Comfort Height Pan & Cistern - White
87969 nuie Freya Pan, Cistern & Seat
87970 nuie Freya Comfort Height Rimless Toilet Pan, Cistern & Seat - White
87978 nuie Ava Pan, Cistern & Seat
87979 nuie Ava Flush Rimless Toilet Pan, Cistern & Soft Close Seat - White
87980 nuie Ava Comfort Height Toilet Pan, Cistern & Seat - White
87983 nuie Ava Pan, Cistern & Seat
87984 nuie Freya Pan, Cistern & Seat
87985 nuie Freya Pan, Cistern & Seat
88017 nuie Melbourne Pan & Cistern
88022 nuie Ivo Pan & Cistern
88023 nuie Ivo Comfort Height Pan & Cistern
88032 nuie Doc M Pack Comfort Height Pan & Cistern - White
92167 BC Designs Victrion CC Pan & Cistern Inc Fittings - White
92171 BC Designs Victrion Pan, High Level Cistern & Pipe - White
92175 BC Designs Victrion Pan, Mid Level Cistern & Pipe - White
93158
93159
93797
94450
94796
94797
94802
94803
94807
94808
94826
94842
95555
95738
95739
95740
95741
95742
95754
95819
96529
98416
99139
99140
99148
99149
99150
99156
99157
99159
99160
99161
99196
99201
99210
99211