SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e538f64f0fbace63dcbeb0d8d8e79954ac5c33aeff3972789e139720bdf49115' 
  AND token = 'H2mmW69doXQooP+9gipF8tgiHICqfyyMWxmz/GIoYDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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