SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92812f4d801ed0bf48b8d88e37e441238b6e630bcfbdc9b21ef880464390be14' 
  AND token = 'cB9DAgWjhIHQjEPHFwYkGISs+A8OeQb+Za3WYCsXoCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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