SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccfb56769b94fd4e9c073d0690fcd597f25db5c8fd0caecc25f7bba0e6c4a513' 
  AND token = 'Dwq9qjGavgyMJGaDbcrTPuyv+n9blUcAWmkBie92VbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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