SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '395641cffbd91baeec2850155c073f483276c79e11ffd749c646c05aef642760' 
  AND token = 'zdIaqezelV5u9i5iDr3EfMQicD54fQ82ldFzcO0+jMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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