SELECT 
  * 
FROM 
  cscart_vd_vendors_relationships 
WHERE 
  brand_id = 153

Query time 0.00040

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
12821 153 661 2198 es
12820 153 649 1924 es
12819 153 648 1899 es
12818 153 654 2140 es
12817 153 654 2137 es
12816 153 654 2136 es
12815 153 654 2135 es
12814 153 647 1889 es
12813 153 662 2212 es
12812 153 660 2188 es
12811 153 658 2186 es
12810 153 652 2104 es
12809 153 652 2106 es
12808 153 652 2116 es
12807 153 646 1887 es
12806 153 653 2128 es