SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c536fc6a78315b1b1ea48b2f4787444205ba2b2911b87f6f43935fba7bbb054' 
  AND token = '0CdLoWgI9h2VDjvhfwc9/N+/JfFFz1CBl4fuB4Ox/4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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