SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '911fb856228fb2d9395ccbd0b790e476cff1de892429fe31ed47de9e9b7afd46' 
  AND token = '0I7U5zXykAYZPvuyhzWjJrpR0MwrX9yNqsiYW2yeP1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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