SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1b101b3ea76d5266d58f854f71225c98f3bfd4b75a9980b69a49c91a5bb7804' 
  AND token = 'GNURv4shpwjHmXVamRv681CpYoVwPjM8KlI+ngC+y8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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