SELECT 
  * 
FROM 
  `cscart_category_vendor_product_count` 
WHERE 
  `company_id` = 692

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "0.80"
    },
    "table": {
      "table_name": "cscart_category_vendor_product_count",
      "access_type": "ref",
      "possible_keys": [
        "PRIMARY"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "company_id"
      ],
      "key_length": "4",
      "ref": [
        "const"
      ],
      "rows_examined_per_scan": 3,
      "rows_produced_per_join": 3,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "0.50",
        "eval_cost": "0.30",
        "prefix_cost": "0.80",
        "data_read_per_join": "48"
      },
      "used_columns": [
        "company_id",
        "category_id",
        "product_count"
      ]
    }
  }
}

Result

company_id category_id product_count
692 659 1
692 700 6
692 888 1