SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c160ac95e234509f79d349695e3da33149f188b98421639336fcbcb14719fbb' 
  AND token = 'vOtTP/qjFHHzLgxmx8Yqjv+7WwP7skWDMnkK50Es+JY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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