SELECT 
  COUNT(*) AS cnt 
FROM 
  cscart_vendor_locations

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.00693929,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_vendor_locations",
          "access_type": "index",
          "key": "locality_country_idx",
          "key_length": "292",
          "used_key_parts": ["locality", "country"],
          "loops": 1,
          "rows": 2,
          "cost": 0.00693929,
          "filtered": 100,
          "using_index": true
        }
      }
    ]
  }
}