SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9f495cdc077e2ab94e748652743a3cc5f158a3645f55b3854a32f73aa885973' 
  AND token = 'vnKORfW618uGhMDybmZBI2EelwiU3D4eWDy1m1wUmVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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