SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c015ce743b71c3d336a942800a2ac4288fdb1b39fb2b932253e2ae65a2af0976' 
  AND token = 'Gz4ruHLbOg5genymPrLLwkg9M2AOMwaXiPnQa3l/xjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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