SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d441fd264ffa3971da710682079d427372d68a38804a87891b0b730e759137c' 
  AND token = 'peLfkZURx5lsIJrRswzykgA4Dr124tbwyBeH6F4QuBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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