SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b52c3404582f72036b9d5cc898c25b7c9253fd9a873e3a677b27c032f33b5cc' 
  AND token = '6jnCVXGgqsG4jCbYHuohW/h3OyjQZkusw40h2BDlTuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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