SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0476fdeb889caf1e6f340b4752ab0980ae14d216b23bf57cc207dc31926b0098' 
  AND token = 'pttAzfXZXkUFKBdBWN0PwKKnlRafunBuDbhfk6rX9NM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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