SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0496c635e31dcab50920aeaa40000d25a1ef47feca7fa7ed9d24a69e42aa96bf' 
  AND token = 'B7yqk+JkVKvyhgFqhQFXHgD5YvOJxeZ8Xr0ljOZ5KEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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