SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33ce32ee82b67513092717bdc9284e2bec0eaa67a731ddfb9bed720aafda25ca' 
  AND token = 'S7xoS9eoN7+9OeOvM+j4heUMDeK+9w+WRkzDWwkmqis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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