SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fcdac0580f35eb522c5b22b27feb155cbe5de8996a8d40b219a437aed6d91bf' 
  AND token = 'HBZx3N+ErYUkTiQ64K5tBlIDnrml6DvGHIZYS+Up/3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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