Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8a8d6e67533363a1228ad7cfd9fda199d316acb44c341c36ef5835694add6f8' 
  AND token = 'ZB81kiBrWBMnowHoIps296T2CtYzi91xgm+dGrxWA4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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