SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7889cf6931bf6d7751e2f0e004c042e5e0952cdc23de6f1164ff931472f936a3' 
  AND token = 'nxQRMrzf4aNvyqaFtKc0TDx5iRycQn1PS1fzqKOUfco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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