SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ee2b199c04913d58915e925c61e929eaa401a96531a3a95de0035871881c88b' 
  AND token = '+z3Wx3+X2VKjA3drUYFeG9hgn6QXn1HKjZE4N45nZU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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