SELECT 
  * 
FROM 
  cscart_vd_vendors_relationships 
WHERE 
  brand_id = 143

Query time 0.00083

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_vd_vendors_relationships",
          "access_type": "ref",
          "possible_keys": ["brand_id"],
          "key": "brand_id",
          "key_length": "4",
          "used_key_parts": ["brand_id"],
          "ref": ["const"],
          "rows": 11,
          "filtered": 100
        }
      }
    ]
  }
}

Result

id brand_id feature_id variant_id lang_code
12508 143 661 2198 es
12507 143 649 1925 es
12506 143 648 1905 es
12505 143 654 2140 es
12504 143 647 1889 es
12503 143 662 2211 es
12502 143 660 2188 es
12501 143 658 2180 es
12500 143 652 2105 es
12499 143 646 1886 es
12498 143 653 2128 es