SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c285e39eef0bce8df5d552266b893ab20e9f57724de372f6487c392456e4e41' 
  AND token = 'pLJOyuuwHztG9C2hwldg5rkguK08BooW2HPRTHy+ZBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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