SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daf39d5780a9e5cf9812a40cf561d6380a795696a850b70876bc618c19494df0' 
  AND token = 'ZwNDkFtx7CrP4Rljl6CnOhH/+eOPInuRks5vnHDZulU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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