SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f29c7389e33440cd5e85a9bc891672ef8fdf18a5887853359ed50b30b8a3b63c' 
  AND token = 'u04w+7IdqHPER1PK05hcD4WsVGBNrWYT+dusgMvm/50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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