SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84dc785b9ef799f6714a8b40577a61b29f682312435dcacd852061cc23b1b29c' 
  AND token = 'VIVoiBmtliuEJADQcLOYgJ5cXoiDPa3/ufvA+kHZ3ak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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