SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a29b433b529d731a3b5dbf93034765f3d5aea32f19e3d40bce24d27e58b55b5c' 
  AND token = 'B6C3pnZ+pxdZzACi+PdDfuJatpFeGak8JFkGF0Ncqik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00071

JSON explain

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