SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd4403f669ced7d82d5da0c97e3fa66576621ab5ccbec51590e667cab5ff05f6' 
  AND token = 'ZLj13lgb93dlalYXwWwRVljI1ZKKRa4PQ0nBzYi7ox4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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