SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc0129686f70a7fbf0863fb5f835235eeae9318bef3ed57aebfa6dc014546f77' 
  AND token = 'oHsG3xzBFD+W/JFJf8nl9+buBg2YzMaRUn+g6x/DZtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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