SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e5c2460f3380615504d9dbd8d1e14dde2f9898ffa3b0ac22dc4464ee3caccc5' 
  AND token = 'cF5WsbCZpE5sOJlgHAUqg1QDQBd8n9dch5SfILdtZVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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