SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7387f9805225b058c1ad4b98deb8455461d56f477e77ea533b1098f7989cf0ec' 
  AND token = 'Uku7UQtfW503jdqYK0GaRxmFIcP3psBnFVIHVS3H9nM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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