SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c3925da2204545deac685e7daa8eaea1f0a82fa3895e54f08f281509d99e3c6' 
  AND token = 'iTUzkc7OXqUxKhAjugc7Z+zuRg6PMQi3U6RM0ELeNKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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