SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '262c22286c271d435ff49dfb01e0502264e4748fb9d35b04daccc4f0eb6d8ff6' 
  AND token = 'TB5SuRHUqoprTrMfzUXy5OcUhNtpxLEx7G6eSygQKos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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