SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '168a593359f5f2600cb069d05c32d9845bf43bfbe60e73ea2927a5bf595d8ab4' 
  AND token = 'SjReDdyNM8JzOwmjITi7Q+IzY7TBy8fPUaqrRkwZKzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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