SELECT 
  * 
FROM 
  cscart_vd_vendors_relationships 
WHERE 
  brand_id = 222

Query time 0.00048

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": 18,
          "filtered": 100
        }
      }
    ]
  }
}

Result

id brand_id feature_id variant_id lang_code
14620 222 661 2198 es
14619 222 649 1925 es
14618 222 648 1897 es
14617 222 654 2142 es
14616 222 654 2140 es
14615 222 654 2137 es
14614 222 647 1889 es
14613 222 662 2205 es
14612 222 660 2187 es
14611 222 658 2179 es
14610 222 652 2104 es
14609 222 652 2123 es
14608 222 652 2118 es
14607 222 646 1887 es
14606 222 653 2131 es
14605 222 653 2129 es
14604 222 653 2128 es