SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ce9a43f8d7998929038c28cde28ac00872fb514274cabcdac8a378af5eea20f' 
  AND token = 'ttIm54j/qM0ZEhcVl89gICNK1XiHWlt/E9n88NnxQjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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