SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2802ce16c9d3ab064ff6d76207d3d546a3122cd5c4bfba7339b744c06587f4c4' 
  AND token = 'V+1D6wFUsX8+1rZOwk5giJO+4Z48z/cvHJRWdDY9VLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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