SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2aa09a528bcefd058e9a51ad0aada73bec63acc1b7ae1d238d7bbd29bf34f39' 
  AND token = 'myi9lDIqZ6WFjcwtDLnVxOnLd/QXPgK1XsvtMfnUuIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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