SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4df75cff9363e29fb947216d64779fb171829aa45143ebe9c60a258826729d8f' 
  AND token = 'aiOqU2Owsj2SN5P8PPiKhuc7QxvrkGVtD8johqCJ1G0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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