SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b52c155bc8bef10c9094a8969d444db146d3de940a612edb9a7f831caf5ae7c' 
  AND token = 'ZZWwtekO/qXjRh/zrmuEhUOVVYSpxXaUMd/YH09eW5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}