SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c23efd0fd9f9615fc93f11db8ed3dad39845293d14ce2f0666a20a058c505eec' 
  AND token = '7QOJPZ1sdu/uLe/euJqEm5+OWxkiKouro+LAaaj5Hhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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