SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ca285d9cd52eb18abf4b7537bbc641a33123ee34b21cc222ba955e8862a6f0d' 
  AND token = 'UbGHx/sqhaXGNTrrJxjJRVNuVYeznql6nTB376ztZ0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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