SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cba9cc25529d9cc7ea480d1a8624ee556ae9244a0ac05870747e20ff459dfcb' 
  AND token = 'kgtaVa7U97vIYiynAtX6BU8h98HKJjDfpdb9owW5VHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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