SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '573567c6d31965499ddf0cec10fa386ec6d582dc651482676d4fced7f8bd68f3' 
  AND token = 'xZPKJq41zTCFDKxiYsni3rZwjSttrXJciGCAhmxExHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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