SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e6154e240923164bc97851062a96342e92b57cc7b18089d80d687f0d9822ee3' 
  AND token = 'JtUiK8akFxEUPQHhhETcdJjNxme4MNFkOHQuIyTyZjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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