SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8f9a733700d49a94b5050941e031fd6689254187f7e4616097b00fb3666c9ff4' 
  AND token = '1tb7BW3W6wRA9aWUtv4CqY+tenlInQV+vWnFDZGXM2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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