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, 
  product_position_source.position AS position 
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') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 7165 
WHERE 
  cscart_products_categories.product_id IN (
    95352, 95353, 95354, 95355, 95356, 95357, 
    95358, 95359, 95450, 95451, 95452, 
    95453, 95454, 95455, 95456, 95457, 
    95458, 95459, 95460, 95461, 95462, 
    95463, 95464, 95465, 95466, 95467, 
    95468, 95469, 95470, 95471, 95472, 
    95473, 95474, 95475, 95476, 95477, 
    95478, 95479, 95480, 95481, 95482, 
    95483, 95484, 95485, 95486, 95487, 
    95494, 95495, 95496, 95504, 95505, 
    95506, 95507, 95508, 95509, 95510, 
    95511, 95512, 95513, 95514, 95515, 
    95516, 95517, 95518, 95519, 95520, 
    95521, 95522, 95523, 95524, 95525, 
    95526, 95527, 95528, 95529, 95530, 
    95531, 95532, 95533, 95534, 95535, 
    95536, 95537, 95538, 95539, 95540, 
    95541, 95542, 95543, 95544, 95545, 
    95546, 95547, 95548, 95549, 95550
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01560

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "86.69"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "link_type",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 96,
            "rows_produced_per_join": 96,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "9.89",
              "eval_cost": "9.60",
              "prefix_cost": "19.49",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (95352,95353,95354,95355,95356,95357,95358,95359,95450,95451,95452,95453,95454,95455,95456,95457,95458,95459,95460,95461,95462,95463,95464,95465,95466,95467,95468,95469,95470,95471,95472,95473,95474,95475,95476,95477,95478,95479,95480,95481,95482,95483,95484,95485,95486,95487,95494,95495,95496,95504,95505,95506,95507,95508,95509,95510,95511,95512,95513,95514,95515,95516,95517,95518,95519,95520,95521,95522,95523,95524,95525,95526,95527,95528,95529,95530,95531,95532,95533,95534,95535,95536,95537,95538,95539,95540,95541,95542,95543,95544,95545,95546,95547,95548,95549,95550))"
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "nuie_scalesta_net.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 96,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "24.00",
              "eval_cost": "9.60",
              "prefix_cost": "53.09",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "nuie_scalesta_net.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "24.00",
              "eval_cost": "0.48",
              "prefix_cost": "86.69",
              "data_read_per_join": "12K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`nuie_scalesta_net`.`cscart_categories`.`storefront_id` in (0,1)) and ((`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`))) and (`nuie_scalesta_net`.`cscart_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}