SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90e305797749671455b34a57fb7fa0e5a4c369ea8faf84833eae2a3d9cdf843d' 
  AND token = 'Nv5swiokNR4IuBIKW/aBjgrjnAOjsD06bqlnW06xx9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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