SELECT 
  * 
FROM 
  cscart_vd_vendors_relationships 
WHERE 
  brand_id = 213

Query time 0.00039

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": 14,
          "filtered": 100
        }
      }
    ]
  }
}

Result

id brand_id feature_id variant_id lang_code
14361 213 661 2198 es
14360 213 649 1925 es
14359 213 648 1919 es
14358 213 654 2141 es
14357 213 654 2140 es
14356 213 654 2137 es
14355 213 654 2135 es
14354 213 647 1889 es
14353 213 662 2219 es
14352 213 660 2188 es
14351 213 658 2180 es
14350 213 652 2114 es
14349 213 646 1886 es