SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fd405e0a8d369a55b2deb791f5eeebfeba9d9a455291b95eb9b16b32be48fb5' 
  AND token = 'eMWZrbBsSrog/ZeNkfIk+HUjPfsJZKZd10437U3xEnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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