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 (
    120, 121, 122, 123, 124, 125, 126, 127, 
    128, 129, 130, 131, 132, 133, 134, 135, 
    136, 137, 138, 139, 140, 141, 142, 143, 
    144, 145, 146, 147, 148, 149, 150, 151, 
    152, 153, 154, 155, 156, 157, 158, 159, 
    160, 161, 162, 163, 164, 165, 167, 168, 
    169, 170, 171, 172, 173, 174, 175, 176, 
    177, 178, 179, 180, 181, 182, 183, 184
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00109

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "37.43"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "1.88"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 84,
            "rows_produced_per_join": 3,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "19.53",
              "eval_cost": "0.67",
              "prefix_cost": "20.20",
              "data_read_per_join": "8K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`pankajecarter_systemfour`.`cscart_categories`.`storefront_id` in (0,1)) and ((`pankajecarter_systemfour`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`pankajecarter_systemfour`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`pankajecarter_systemfour`.`cscart_categories`.`usergroup_ids`)) and (`pankajecarter_systemfour`.`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": [
              "pankajecarter_systemfour.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 3,
            "rows_produced_per_join": 1,
            "filtered": "18.64",
            "index_condition": "(`pankajecarter_systemfour`.`cscart_products_categories`.`product_id` in (120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184))",
            "cost_info": {
              "read_cost": "13.34",
              "eval_cost": "0.38",
              "prefix_cost": "35.55",
              "data_read_per_join": "30"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
120 237M
121 244M
122 208M
123 244M
124 208M
125 237M
126 251M
127 209M
128 251M
129 209M
130 251M
131 209M
132 182M,179
133 182,179M
134 182M,179
135 182M,179
136 249M
137 249M
138 249M
139 249M
140 180M
141 180M
142 180M
143 180M
144 180M
145 179M
146 179M
147 179M
148 179M
149 179M
150 210M
151 210M
152 210M
153 181M
154 181M
155 181M
156 181M
157 181M
158 253M
159 253M
160 210M
161 199,198M
162 253M
163 199,198M
164 199,198M
165 199,198M
167 197M,199,198
168 197M,199,198
169 198,197M,199
170 212M
171 252M
172 199M
173 199M
174 252M
175 199M
176 252M
177 212M
178 252M
179 212M
180 200M
181 212M
182 252M
183 200M
184 200M