SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5026cb8dd7846b05391e633b7817b283bc22daf109fbd365f58a0eb5cf5372e' 
  AND token = 'eKJGzK/li/XYbUSphNs8JhX8BxnwXCazYhGrN6DKp78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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