SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17f4443d25cbf91655a09baace7cc0ffccb2985ee484da136ba9d05f142666e2' 
  AND token = 'ku0ASfSG5rv54q5dKgnKLzj2htJVidY+ZKvXBXRETsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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