SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b234731d0bf02d524fab8a626b1e0bf2f9bc37f92e4c54e3bbad4d5910aad72' 
  AND token = 'ZYsBQa4oS15v0XRmNnWCQdGZsSvqzaIf6ALtzdhqzdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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