SELECT 
  filter_id, 
  feature_id 
FROM 
  cscart_product_filters 
WHERE 
  status = 'A'

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_filters",
      "access_type": "ALL",
      "rows": 13,
      "filtered": 100,
      "attached_condition": "cscart_product_filters.`status` = 'A'"
    }
  }
}

Result

filter_id feature_id
1 0
7 15
8 16
9 17
314 3529
315 3534
329 549
330 548
331 18
332 3541
333 3542
335 0
336 3577