SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '159e1cb9be984be41eba837d490ab8b6ede8cef9172f202b196cc374eccbb774' 
  AND token = '05fkFcB9hj7YmJqxsNala+kidXnjUXdqoTHPQEihkFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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