SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36b9c08fe4b7b74240779499d752341be17a090420c8d8dc51e1f4788628dc31' 
  AND token = '5HKxCf/PSCcDoy4b0rFJZUgsHDzpJRziq5ESo+dBwHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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