SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd5c398fed13593863d256719dddbf270c788f8d029254ce8bf6b0c45acc8e53' 
  AND token = '3hUfcbu0VbtWeiiSmTujboKFag/BtBPFSWIB6ZGNqLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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