SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2403dd50bb72c195b3a3c6ed8cb83c0d31ae85d7ace90794f39f8344b66ad029' 
  AND token = 'BNcap9gibiL7BxHJiHVaY4BuEAbTs4L9QQAaJJ6kAW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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