SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '224d15b3c65dea33ee4cbd2ceb094b9fb6dc8aba1b31761460926423a68b18d5' 
  AND token = 'OVM53tbqdQA+8v2KPylBln/QncUPWSyqzcU3qzSIrXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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