SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fdfb8980a08f39596846625f97e568b74b886cc9a6c0301f85b8e0369edb0cc' 
  AND token = 'DAqt25XHtP/fNlI8SduqDkXJ5SLg2URkmF6hB79vZIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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