SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3426903e8873bdd47bb26ee13a7c983ae1aa0ddb83b7bdb02616a5f9b0cb7279' 
  AND token = 'OrD3EFQ/2dY142Pw+dq/DgzwydWsAUTVlKmQp8yN4Z8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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