SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9e3e2c1412d328f413b854c921ac3ca1a3fe635086efd9f09a25949ce9665a0' 
  AND token = 'zw9DM5wdg/GK1k/MgmV9dx/ahixE8CH1NRr0imTe2Xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00222

JSON explain

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