SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '926bb0493d4164b1c638e24f09207f4f122b0438078cb69ef204ee2ee344c3c7' 
  AND token = 'ONFpENyxQCh6iKPk+IozKkv4WMxoKQ4NPVgLpTxsbno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}