SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aebe8fa5490c3c1cd2680dbdb6eb1c62e54ccda55ab6adf444a07acd558e593a' 
  AND token = 'g2L1lE03TkcU75lJAcGqhuwCZj7ivkd/jxWzBLuZraY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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