SELECT 
  * 
FROM 
  cscart_vd_vendors_relationships 
WHERE 
  brand_id = 111

Query time 0.00046

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": 22,
          "filtered": 100
        }
      }
    ]
  }
}

Result

id brand_id feature_id variant_id lang_code
11563 111 661 2198 es
11562 111 649 1925 es
11561 111 648 1897 es
11560 111 654 2141 es
11559 111 654 2140 es
11558 111 647 1889 es
11557 111 662 2222 es
11556 111 662 2211 es
11555 111 662 2208 es
11554 111 662 2205 es
11553 111 660 2188 es
11552 111 658 2185 es
11551 111 652 2110 es
11550 111 652 2112 es
11549 111 652 2103 es
11548 111 652 2105 es
11547 111 652 2116 es
11546 111 646 1886 es
11545 111 653 2128 es