SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6261de50314645f54a7b46d60a2d0dac22ea9d0c69afc829a1b153a1932e3299' 
  AND token = 'ICj/z4raY/gZBltLPimmuGzDTZHQq9BgLS/nw7WhneE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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