SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eff833546616a71f4f94ffd1546b1c4da1b93ddaa262099bed193ea705f72f9c' 
  AND token = 'jpA4JyShUZvEM3PHhK68sYy4qjXMII0l+kpnpxiUm3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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