SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30851031da8c1aaf2ab68d3018d54bf404fb1e68e400f825aca768994ddfe47c' 
  AND token = 'lJV4BnP1yjUh7Yx1RUBTVFaEk60Nqi+GzWTS6F/TB30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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