SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fe2ab1f0cc6fc8b6e74fae8d2e90bfaa39e3fb87fd39a5ce567dc55ccd5afd57' 
  AND token = 'ak4dpmD+diTcO1gsq4x/svlRfS783iJk75ecbw7+TQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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