SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfdb431978fda550d47426003df501078af512653f2411fb393d48cfa0d4cd5d' 
  AND token = 'PesPqhBWmty5mk6ga0ky+utC5o+DOsdzIaBppu692K8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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