SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05b02552ee798d4b55e1471b148e45a7ac3656325a99e83b5bb5b19334ae5d33' 
  AND token = 'h5ay5oFj+w4BXWCFvW7EbB+5fMMdvWVTer2jhoD0EiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}