SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7652c69b9e540133f44b88c82ee2a9a2f63d9bae6cfe9a07f2077ddfdc215bd9' 
  AND token = 'oMGQ2xLaVj/Y2i9WWIJ+WM+jYkW4pwXcHh8KmIguyZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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