SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19651d5cca35190af835fee4358933a2f0ab52a6017d675abe65092be46d8743' 
  AND token = 'QSQpi3jzvljaWCAL8pYw7/q4BV6PJ1eD8Z1641C6KRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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