SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a3e99ebe1ce3f9b965b27145d0adcae2ec8025b90155ad49b2cb4964cd770b8' 
  AND token = 'XVjDUsFWoUMbpnb+M2hHNrUg+HQuSNC/UwVo9tmC3XA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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