SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '822dc1c641a9a2f8d1cc0e8d4b5bf7ab76f20c641e8c1a4ec0245176688f685f' 
  AND token = 'MUP0FIMBBhHd+7CqtJBzbssWy8KUspF0t09s9XJikgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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