SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f50e334de79ecb7c3819bd5f902be4167cf71c65920e5d76fa0087c0ceeef9e2' 
  AND token = 'BG9VxXrrvXz+hWdvqFlqgOWbdnW1hzlwHKJBGMhZNvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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