SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6addbf2ab900efd1e1d4cf0e66feed40e5c1f5e4dabfb0d89e809830b3f2435e' 
  AND token = 'e3K6XZ+QMrf3PC+3ycOlTZUt034kPDWdxndQJcxeGbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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