SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b87f85d8a27711ef2e361bbbd752c73619a7307a85f6b0f88d64fd3f747d7c6' 
  AND token = 'VnXy5CKjLLES5ezwiF+ESNMmwK1YPkJ3wVLe+5xZF/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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