SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b24750d0705185768d6de4c55bdbc5e244dcef1c64f62ac2b566ed9cbe08b86' 
  AND token = 'uwlt1xOmGqbXHn0kX0ZWMthVIyfUDNRiJq6oOtiL6kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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