SELECT 
  q_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      q_products_categories.link_type = "M", 
      CONCAT(
        q_products_categories.category_id, 
        "M"
      ), 
      q_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  q_products_categories 
  INNER JOIN q_categories ON q_categories.category_id = q_products_categories.category_id 
  AND (
    q_categories.usergroup_ids = '' 
    OR FIND_IN_SET(0, q_categories.usergroup_ids) 
    OR FIND_IN_SET(1, q_categories.usergroup_ids)
  ) 
  AND q_categories.status IN ('A', 'H') 
  LEFT JOIN q_products_categories AS product_position_source ON q_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 190 
WHERE 
  q_products_categories.product_id IN (
    45932, 45933, 45934, 45935, 45938, 45939, 
    45940, 45944, 45945, 45946, 45947, 
    45949, 45950, 45951, 45952, 45953
  ) 
GROUP BY 
  q_products_categories.product_id

Query time 0.00098

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "84.41"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "q_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 18,
            "rows_produced_per_join": 18,
            "filtered": "100.00",
            "index_condition": "(`portal`.`q_products_categories`.`product_id` in (45932,45933,45934,45935,45938,45939,45940,45944,45945,45946,45947,45949,45950,45951,45952,45953))",
            "cost_info": {
              "read_cost": "37.61",
              "eval_cost": "3.60",
              "prefix_cost": "41.21",
              "data_read_per_join": "288"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "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",
              "portal.q_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 18,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "18.00",
              "eval_cost": "3.60",
              "prefix_cost": "62.81",
              "data_read_per_join": "288"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "table": {
            "table_name": "q_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "portal.q_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 3,
            "filtered": "20.00",
            "cost_info": {
              "read_cost": "18.00",
              "eval_cost": "0.72",
              "prefix_cost": "84.41",
              "data_read_per_join": "9K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "(((`portal`.`q_categories`.`usergroup_ids` = '') or find_in_set(0,`portal`.`q_categories`.`usergroup_ids`) or find_in_set(1,`portal`.`q_categories`.`usergroup_ids`)) and (`portal`.`q_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
45932 202M
45933 202M
45934 429M
45935 193M
45938 202M
45939 202M
45940 202M
45944 202M
45945 202M
45946 202M
45947 202M
45949 202M
45950 202M
45951 193M
45952 202M
45953 193M