SELECT 
  c.* 
FROM 
  cscart_bm_containers as c 
WHERE 
  1 
  AND c.location_id = 30 
  AND c.company_id = 0

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "1.05"
    },
    "table": {
      "table_name": "c",
      "access_type": "ref",
      "possible_keys": [
        "location_id",
        "location_id_company_id",
        "location_id_position_company_id"
      ],
      "key": "location_id_company_id",
      "used_key_parts": [
        "location_id",
        "company_id"
      ],
      "key_length": "7",
      "ref": [
        "const",
        "const"
      ],
      "rows_examined_per_scan": 3,
      "rows_produced_per_join": 3,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "0.75",
        "eval_cost": "0.30",
        "prefix_cost": "1.05",
        "data_read_per_join": "1K"
      },
      "used_columns": [
        "container_id",
        "location_id",
        "position",
        "width",
        "user_class",
        "linked_to_default",
        "status",
        "company_id"
      ]
    }
  }
}