SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f83dcc64e90cee77554c6721dfbba7bf642e3292f1ee6fdb414c573fd3e0b21f' 
  AND token = 'QHdVBFN+igUfbTpP0zfbASYcIEbXCBZ0gPBof8LQXkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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