SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01216b9f395ddb6226182542a80e0e681b0e1de10fe61fb93f4ca7b74a7c3cba' 
  AND token = '7tAkS+Q09+Es9vjmgBSwWy+lLkvKXih6VDlJBypFP3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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