SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76414c7920351e2e2a9b91ad8c18dd1610e54ca1348b8d69528cb5f046deed10' 
  AND token = 'pXLc8wOeI0W7S730LC+dSzRGDOA6mOiYLYgoCZ113gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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