SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25cf973bb56dedecc4b6bc0bbe9c0bd324df5f074f15900cc6085072b4d650e1' 
  AND token = 'LICaX2bt9EMjHoQc9Zyt3zImcW671xxd8qwKYv2fgZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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