SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9310a8b0ff8954998c5984c9b4fd9bd8a37ee2794a0eac778842529ba965f4cb' 
  AND token = 'jHI0HEy5SXTcfkd5YhGpoeydFl5jG118NpAKFruCm1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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