SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1dd441ec8f7cc3adbe0e19a9462f283e8176d91fa5aaa7ea654790b3325c96f' 
  AND token = 'S6qxXrvT4k/5YNFIgTz1E/SUZOLHBVWq/PpqgW+80nI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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