SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb3f59055ced582c1139c81085b11b5b643b1fa8c414a66979d3d220563beee4' 
  AND token = 'XmCDxjuaa35EMkX3NgPVbkeVbgwpm/wyF9ipMFPJlXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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