SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
WHERE 
  cscart_products_categories.product_id IN (
    165, 166, 86, 106, 105, 247, 101, 33, 32, 
    163, 244, 212, 155, 102, 55, 176, 69, 
    138, 110, 36, 206, 28, 184, 183, 133, 
    132, 125, 120, 223, 225, 224, 146, 147, 
    93, 117, 219, 222, 220, 221, 87, 113, 
    139, 118, 83, 157, 123, 174, 171
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00082

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "37.18"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "1.53"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 98,
            "rows_produced_per_join": 3,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "22.48",
              "eval_cost": "0.78",
              "prefix_cost": "23.26",
              "data_read_per_join": "13K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`danishecarter_25_march`.`cscart_categories`.`storefront_id` in (0,1)) and ((`danishecarter_25_march`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`danishecarter_25_march`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`danishecarter_25_march`.`cscart_categories`.`usergroup_ids`)) and (`danishecarter_25_march`.`cscart_categories`.`status` in ('A','H')))"
          }
        },
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "danishecarter_25_march.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 2,
            "rows_produced_per_join": 1,
            "filtered": "19.57",
            "index_condition": "(`danishecarter_25_march`.`cscart_products_categories`.`product_id` in (165,166,86,106,105,247,101,33,32,163,244,212,155,102,55,176,69,138,110,36,206,28,184,183,133,132,125,120,223,225,224,146,147,93,117,219,222,220,221,87,113,139,118,83,157,123,174,171))",
            "cost_info": {
              "read_cost": "10.82",
              "eval_cost": "0.31",
              "prefix_cost": "35.65",
              "data_read_per_join": "24"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
28 225M
32 176M
33 176M
36 220M
55 187M
69 236M
83 246M
86 238M
87 246M
93 248M
101 238M
102 227M
105 238M
106 238M
110 243M
113 237M
117 237M
118 244M
120 237M
123 244M
125 237M
132 182M,179
133 179M,182
138 249M
139 249M
146 179M
147 179M
155 181M
157 181M
163 199,198M
165 199,198M
166 198M,199
171 252M
174 252M
176 252M
183 200M
184 200M
206 171M
212 172M
219 169M
220 169M
221 169M
222 169M
223 165M
224 165M
225 165M
244 168M
247 165M