SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9cce659743c6f023379840a93ce10c52a7797dd218855eca7e364db5787e661' 
  AND token = 'pFjXe0vkThYAZgFZcpPIfQPnAzchjhCswkshpo8e6Xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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