SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff937c0c955cd86ae641ebb2ed318478d5ee9fb44b9312a351308e588be89070' 
  AND token = 'uHNWGMKursFYgI/oaQnNRDGXI68WwDrN9+VlZtra9oI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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