SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9445340ce85da1b08c86d4f6ff1533fb1e9070054e80f623919dd95d7b34467' 
  AND token = 'zgNstiyIq7rmEhh/t7vmz9YAO6m2aZW+gnPbKRO5J3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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