SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cccbd2721d6a0a6242d6e0d9e6fc54e048d79052a5f24274a4e7d6078d32bf52' 
  AND token = 'TVmhzdlAvlT9waHEoDiWXTGIObWFtylrRh7WwLMqIBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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